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Ring modulation

Ring modulation is a technique in and audio that multiplies two input signals—a and a modulator—to produce an output containing only the and of their frequencies, while suppressing the original frequency and eliminating the individual input components. This results in a non-linear frequency-domain transformation that generates new sidebands, often creating metallic, clangorous, or bell-like timbres without the fundamental tones of the inputs. Invented in 1934 by Frank A. Cowan at Bell Laboratories for multiple signals over lines, ring modulation was patented in 1935 and initially served purposes by enabling efficient without carrier transmission. In the , it gained prominence in electronic music through designs by engineer Harald Bode, who adapted it for synthesizers like Robert Moog's early instruments, marking its shift toward creative audio applications. Analog implementations typically employ a ring —four diodes arranged in a ring configuration driven by transformers—to achieve balanced , producing double-sideband suppressed-carrier (DSB-SC) signals that require filtering to isolate desired frequencies. Digital versions, common in modern software and hardware, simulate this process with reduced noise and greater precision, allowing real-time and alteration. Widely used in music synthesis since the mid-20th century, ring modulation produces distinctive effects such as the robotic voices of 's Daleks, eerie soundscapes in films like (1956), and experimental textures by artists like and Kraftwerk. In communications, it facilitates suppressed-carrier AM transmission for bandwidth efficiency, while in sound design, it enables unique harmonic manipulations, from steel drum emulations to spaceship noises, often integrated into synthesizers, effects pedals, and vocal processors.

Fundamentals

Definition and Principles

Ring modulation is a nonlinear technique that multiplies two input signals—a carrier signal and a modulating signal—to produce an output consisting primarily of sum and difference components, while suppressing the original of both inputs. This process, also known as frequency mixing, generates new spectral content through , distinguishing it from linear operations like simple addition or filtering, which preserve the input frequencies without creating harmonics or sidebands. At its core, ring modulation operates as a form of without a residual , where the modulating signal directly scales the amplitude of the instantaneously. In ideal conditions, the output lacks the 's , resulting in a double-sideband suppressed- (DSB-SC) signal that emphasizes only the sidebands around the . This suppression occurs because the effectively cancels the component of the when the modulator oscillates symmetrically around zero. Mathematically, the time-domain output is expressed as
y(t) = x(t) \cdot c(t),
where x(t) represents the modulating signal and c(t) the signal. In the , this multiplication equates to the of their respective spectra, Y(f) = X(f) * C(f), yielding energy at frequencies f_c + f_m (sum) and |f_c - f_m| (difference), where f_c and f_m are components of the and modulator spectra, respectively. For sinusoidal inputs, this produces discrete sidebands; for complex signals, it generates a dense array of products. The nonlinear nature of ring modulation—arising from the multiplicative interaction—contrasts with linear modulation schemes, such as , by introducing these new frequency terms that can enrich or distort the signal depending on the input characteristics. This assumes familiarity with basic , including transforms, where linear systems output sums of input spectra without alteration, whereas nonlinear systems like ring modulation produce convolutions that expand the bandwidth.

Frequency Components

In balanced ring modulation, the output spectrum consists primarily of the upper and lower sidebands generated from the carrier frequency f_c and the modulator frequency f_m, specifically at f_c + f_m and |f_c - f_m|, while the original carrier and modulator frequencies are suppressed. This spectral transformation arises from the trigonometric product-to-sum identity applied to sinusoidal inputs: \sin(2\pi f_c t) \sin(2\pi f_m t) = \frac{1}{2} \left[ \cos(2\pi (f_c + f_m) t) - \cos(2\pi (f_c - f_m) t) \right], which yields only the sum and difference terms without residual components at f_c or f_m. The absolute value in the difference frequency accounts for the fact that spectra are conventionally plotted for positive frequencies, mirroring negative components. For a single-tone modulator, such as a pure at f_m = 100 Hz combined with a at f_c = 1000 Hz, the resulting features discrete lines solely at 1100 Hz and 900 Hz, forming symmetric sidebands around the suppressed without any central or original tones. In contrast, a multi-tone modulator—such as a complex signal like speech containing multiple harmonics—produces a dense array of sidebands, where each modulator component generates its own pair of sum and difference frequencies relative to f_c, often resulting in a broadened, metallic with numerous closely spaced spectral lines. Phase shifts play a key role in the modulator's , particularly through the 180-degree inversion of the modulator signal during the negative half-cycle of the , which ensures symmetry in the output and contributes to the effective suppression of and original components in the . This inversion affects the relationships between sidebands but preserves the locations, though relative differences between and modulator can subtly alter the perceived without shifting the spectral peaks. In an ideal ring modulator, perfect balance achieves complete suppression of f_c and f_m, assuming infinite and precise symmetry, yielding a clean of only the desired sidebands. However, real-world implementations often exhibit imperfect balance due to component mismatches or finite , leading to of residual carrier and modulator tones, as well as from higher-order harmonics (e.g., odd multiples like $3f_c \pm f_m) that require additional filtering to mitigate.

Historical Development

Early Invention

Ring modulation emerged in the early as a technique for balanced modulation to suppress the carrier signal, enabling more efficient in communication s. However, ring modulation developed as a distinct method after to facilitate carrier elimination in amplitude-modulated signals. The key early invention was patented in 1935 by Frank A. Cowan, an engineer at American Telephone and Telegraph, under U.S. Patent No. 2,025,158 (filed June 7, 1934), describing a modulating using a ring of rectifier elements—typically diodes—arranged in a balanced configuration to produce sidebands without the carrier component. This design improved upon prior balanced modulators by enhancing carrier suppression through the symmetric ring arrangement, minimizing leakage and distortion in the output. Cowan's work was primarily motivated by the needs of multi-channel telephony, where efficient multiplexing of signals over limited lines was essential to support expanding long-distance networks without interference. In the context of radio communications, the technique addressed the growing demand for single-sideband suppressed-carrier () transmission during rise of shortwave broadcasting, allowing transmitters to conserve power by omitting the and one while maintaining over long distances. This efficiency was particularly valuable as expanded, reducing usage and power consumption in an era of limited spectrum resources.

Key Milestones

Advancements in diode technology during World War II laid the groundwork for improved modulator performance and reliability in post-war communications systems. In the post-war era, ring modulation saw commercialization in the through its integration into broadcast equipment, particularly for single-sideband suppressed-carrier transmission, which optimized spectrum efficiency in . In the , Harald Bode incorporated ring modulators into electronic musical instruments like the Melochord, marking an early shift toward audio applications. By the early 1970s, the introduction of integrated circuits advanced the technology further, with Motorola's MC1496 balanced modulator IC enabling compact, high-performance implementations in communications devices. The and marked ring modulation's entry into the audio domain, as Bode collaborated with to develop ring modulator modules for modular synthesizers starting in 1963–1964, where it produced distinctive metallic and dissonant sound effects for electronic music . Up to 2025, developments have shifted toward hybrid analog-digital configurations in systems, combining analog front-ends for initial mixing with digital processing for flexibility, while pure analog ring modulators persist in niche , valued for their warm, unpredictable timbres in pedals and modules.

Analog Implementation

Circuit Description

Analog ring modulation circuits operate as four-quadrant multipliers, enabling the multiplication of two bipolar input signals to produce an output consisting solely of the sum and difference frequency components, without the original carrier signal. This topology relies on a balanced bridge configuration, where the bridge structure ensures that positive and negative excursions of both signals are handled symmetrically, facilitating complete suppression of the carrier in an ideal setup. The balanced nature of the bridge allows for the processing of signals with both polarities, distinguishing it from simpler modulators that may introduce distortion or carrier remnants. In terms of signal flow, the modulator input—often referred to as the or RF signal—is applied across the bridge, while the signal drives the bridge elements, causing them to switch states in a manner that effectively multiplies the inputs. The output is derived differentially from opposite points of the bridge, which inherently cancels the component through opposition, leaving only the modulated sidebands. This differential extraction is crucial for maintaining and achieving the desired frequency mixing without offsets or unwanted harmonics propagating to the output. Achieving effective suppression demands precise balance in the components, with mismatches leading to carrier leakage that can degrade performance. Typically, suppression exceeding 40 is required for practical applications, necessitating careful matching of bridge elements to within tight tolerances, often through adjustable trims or high-precision . Poor balance can result in output , reducing the modulator's in sensitive systems like communications. Circuit variations include transformer-coupled designs, which use input and output transformers to provide , impedance transformation, and enhanced balance for RF environments, and direct-coupled approaches, which eliminate transformers for wider , lower cost, and easier into monolithic or circuits while relying on active elements for balancing. Transformer-coupled versions excel in high-frequency but may introduce limitations, whereas direct-coupled designs offer flexibility for to ranges. Early ring modulators employed diodes in the bridge for this switching action, a that laid the foundation for modern implementations.

Diode-Based Modulators

Diode-based modulators employ a classic configuration consisting of four arranged in a closed , connected between the center taps of two center-tapped . The signal is applied to the primary winding of the first (T1), which drives the across opposite diode junctions, while the modulating signal is fed to the primary of the second (T2), with its center taps connected to the diode . The output is taken from the secondary winding of T2, often across a load , enabling balanced operation that isolates the signals. In operation, the diodes function as switches controlled by the carrier signal's polarity. When the carrier voltage is positive, one pair of opposite diodes (e.g., D1 and D2) conducts, allowing the modulating signal to pass through unchanged; when negative, the other pair (D3 and D4) conducts, inverting the modulating signal. This alternating conduction effectively multiplies the two input signals, producing sum and difference frequency components at the output while the balanced transformer arrangement cancels the original and modulating signals, yielding suppressed-carrier modulation. The nonlinear voltage-current characteristics of the diodes introduce some , but the minimizes even-order harmonics. Suitable diodes include Schottky types like 1N5711 or SB130 for their low forward (around 0.3 ), which reduces and improves suppression, or germanium diodes such as 1N695 for similar low-threshold performance in audio applications; silicon diodes like 1N4148 can be used but may require biasing for better results. Transformers are typically 1:1 ratio with center taps, rated for 10 kΩ impedance and a from 300 Hz to 100 kHz in audio contexts, though higher-frequency variants support ranges up to 10 MHz in radio applications. Diodes should be matched for consistent forward voltages to ensure balance and minimize unwanted signals. For a hobbyist construction, begin with a featuring oversized holes for leads and DIP-compatible footprints. Solder four matched s in alternating orientations to form the between the center taps of two audio s (e.g., SP-66), ensuring the secondary windings face the s for . Attach input jacks for and modulator signals to the primaries, and an output jack across the secondary of the second ; no additional is needed for this passive design. Fine-tuning involves adjusting for balance by swapping s or adding small resistors if breakthrough occurs, allowing operation with line-level audio signals.

Digital Implementation

Algorithms and Methods

In digital signal processing, ring modulation is implemented through direct sample-by-sample multiplication of the input signal x and the carrier signal c, yielding the output y = x \cdot c. This operation produces sum and difference frequencies analogous to analog counterparts, but requires careful management of spectral content to avoid artifacts. To mitigate aliasing from high-frequency components exceeding the Nyquist limit—such as when sum frequencies approach or surpass half the sampling rate—anti-aliasing filters, often low-pass designs, are applied post-multiplication or via techniques like continuous-time convolution approximation. For applications requiring single-sideband (SSB) extraction after ring modulation, quadrature methods employ the to generate an from the modulated output, enabling selective suppression of one . The shifts the phase of negative frequencies by -90 degrees and positive frequencies by +90 degrees, creating a complex representation where multiplication with a complex exponential carrier (e.g., e^{j\omega_c n}) isolates the upper or lower . In practice, (FIR) or (IIR) filters approximate the ideal Hilbert transformer, with designs like 13th-order elliptic halfband filters achieving low-latency phase shifts for audio processing. This approach extends double-sideband ring modulation to frequency shifting effects while preserving the signal envelope. FPGA and ASIC implementations leverage hardware description languages such as to synthesize dedicated ring modulator cores, utilizing on-chip (DSP) slices for efficient multiplication and accumulation. These cores enable processing at high sampling rates by pipelining the sample-wise operations and integrating carrier oscillators. in digital ring modulation involves trade-offs between floating-point and : 32-bit floating-point formats provide dynamic ranges exceeding 1500 dB with minimal quantization distortion, ideal for high-fidelity audio where carrier amplitudes vary widely. Conversely, fixed-point representations, such as 16- or 32-bit signed integers, offer lower power consumption and faster execution on resource-constrained processors but risk and reduced signal-to-noise ratios (approximately 96 dB for 16-bit or 144 dB for 24-bit fixed-point), necessitating scaling and overflow detection mechanisms.

Software and DSP Applications

In digital audio workstations (DAWs), ring modulation is commonly implemented as an audio effect , enabling musicians and producers to apply the modulation in during mixing and performance. For instance, includes ring modulation functionality within its Frequency Shifter device, which performs balanced modulation to produce sum and difference frequencies without carrier leakage, ideal for creating dissonant or metallic tones in electronic music production. Open-source and visual programming environments further democratize ring modulation implementation. Max/MSP, developed by , allows users to build custom ring modulation patches using the *~ object for signal multiplication, supporting complex routing and integration with hardware controllers for live sound design. Similarly, Pure Data (Pd), an open-source alternative to Max, utilizes the *~ object to achieve ring modulation by multiplying input audio with a carrier signal, facilitating portable, cross-platform applications in installations and education. For embedded systems, ring modulation is realized on specialized digital signal processors (DSPs) to handle audio in resource-constrained environments. Platforms like ' TMS320 family, such as the TMS320C6713, support efficient implementation of modulation algorithms through their multiply-accumulate (MAC) units, commonly used in portable audio devices and gear for low-latency processing. ' SHARC processors, including models like the ADSP-21489, provide high-performance floating-point operations for precise ring modulation in professional audio equipment, leveraging SIMD instructions to minimize computational overhead in effects chains. Modern applications extend ring modulation to consumer platforms. Mobile apps, such as Ringotron for , offer advanced ring modulation with features like phase control and selection, enabling on-device for musicians without requiring a full DAW. In web-based audio, the Web Audio API allows implementations of ring modulation via nodes like GainNode for signal multiplication, supporting real-time browser effects in interactive web apps and online instruments. Digital ring modulation provides key advantages over analog counterparts, including exact suppression to eliminate leakage—achieved through precise multiplication without imbalances—and seamless , such as infinite balance adjustments and frequency tuning via software interfaces. However, in live processing scenarios, implementations can suffer from due to sizes and algorithmic overhead, typically ranging from 1-10 depending on the platform.

Applications

Radio Communications

Ring modulation plays a crucial role in suppressed carrier modulation schemes, particularly in generating double-sideband suppressed carrier (DSB-SC) signals that form the basis for single-sideband suppressed carrier (SSB-SC) transmission in radio communications. By multiplying the modulating audio signal with a carrier using a balanced ring modulator, the carrier is effectively suppressed, eliminating the transmission of unused power while producing symmetric sidebands around the carrier frequency. This DSB-SC output is then filtered to retain only one sideband for SSB-SC, achieving bandwidth savings of approximately 50% compared to conventional double-sideband full carrier (DSB-FC) amplitude modulation (AM), as only the necessary spectral components are transmitted. In terms of power efficiency, SSB-SC allocates all transmitted power to the information-bearing sideband, achieving up to 100% efficiency for the useful signal, in contrast to full AM where the carrier consumes about two-thirds of the total power, limiting efficiency to a maximum of 33% for sinusoidal modulation. On the receiver side, ring modulation is implemented via product detector circuits to demodulate the incoming SSB-SC or DSB-SC signal and recover the original baseband audio. The product detector, often a diode ring configuration, multiplies the received radio frequency (RF) signal with a locally generated carrier from a beat frequency oscillator (BFO), producing sum and difference frequencies that yield the baseband after low-pass filtering. This synchronous demodulation ensures accurate recovery of the modulating signal without distortion from carrier remnants, making it essential for high-fidelity reception in SSB systems. The doubly balanced nature of the ring modulator suppresses both the incoming RF and local oscillator from the output, minimizing interference and improving signal-to-noise ratio in the demodulated audio. International standards from the Radiocommunication Sector () have historically endorsed modulation employing ring-based techniques for shortwave () communications to optimize spectrum use and propagation efficiency. For example, the withdrawn Recommendation ITU-R BS.640-3 (1997, withdrawn 2012) specified parameters such as up to 4.5 kHz audio and 5 kHz spacing for in , with at least 12 dB carrier suppression to reduce interference in crowded bands. In modern (SDR) systems, digital implementations of ring modulation—via numerical in —facilitate efficient up-conversion and down-conversion for flexible frequency translation without analog hardware. These digital mixers enable real-time generation and demodulation in SDR platforms, enhancing adaptability for amateur and professional operations. Practical examples in highlight ring modulation's integration, such as in transceiver kits like the uBITX, which uses a diode-based balanced modulator for both SSB transmission and reception across HF bands. This low-cost design achieves carrier suppression and sideband filtering through analog ring modulation principles, supporting efficient QRP (low-power) operations. By the 2020s, hybrid SDR enhancements in similar rigs incorporate mixing akin to ring modulation for improved up/down-conversion, allowing seamless band switching and mode support while maintaining compatibility with traditional HF protocols.

Audio and Music Synthesis

Ring modulation is widely employed in to generate distinctive and inharmonic timbres, often resulting in bell-like or metallic tones that arise from the suppression of original and modulator frequencies, leaving only their and components. For instance, modulating a signal at 440 Hz with a modulator at 550 Hz produces output frequencies at 990 Hz and 110 Hz, creating an eerie, clangorous suitable for experimental soundscapes. This technique excels at producing non- partials when the modulator frequency is not an multiple of the , enabling composers to craft abstract textures that evoke metallic percussion or otherworldly drones. Historically, ring modulation featured prominently in early analog synthesizers, such as the modular systems introduced in 1965, where it served as a core module for voltage-controlled sound generation in compositions. Similarly, the VCS3 , released in 1969, incorporated a ring modulator renowned for its ability to produce clangorous bell tones, which became a staple in by artists exploring electronic abstraction and noise. In contemporary music production, ring modulation persists through dedicated guitar pedals like the Ring Thing, which offers precise control over carrier tuning and modulation depth to achieve sweeping metallic effects on live instruments. (VST) plugins, such as those integrated into digital audio workstations, extend this capability into software-based synthesis, allowing for real-time parameter automation in track production. Beyond music, ring modulation is a go-to method in film for creating robotic or alien voices, as exemplified by its application to vocal tracks in science fiction productions to impart a synthesized, inhuman quality. Key techniques in musical applications include varying the carrier frequency slowly to simulate vibrato-like pitch undulations on sustained notes, adding subtle without altering the core . For enhanced spatial depth, dual ring modulators can be employed in , with one handling the left channel and another the right, to create that widens the perceived soundfield and introduces phasing artifacts. These methods highlight ring modulation's versatility in both subtractive and post-processing effects chains.

Telecommunications

In analog , ring modulation was integral to (FDM) carrier systems, enabling the combination of multiple voice channels over shared transmission media such as coaxial cables and open-wire lines. These systems, exemplified by AT&T's L-carrier introduced in the 1950s, employed ring modulators as balanced modulators to generate double-sideband suppressed-carrier (DSB-SC) signals, which were then filtered to produce (SSB) modulation for efficient utilization in long-distance networks. Ring modulators facilitated voice frequency shifting in multi-channel links by suppressing the carrier while preserving sidebands, allowing 4 kHz voice bands (typically 300–3400 Hz) to be translated to higher without introducing low-frequency components that could interfere with signals. In standard FDM hierarchies, such as the CCITT basic group, 12 voice channels were modulated onto carriers spaced at 4 kHz intervals within the 60–108 kHz band, with pilot tones inserted at specific frequencies (e.g., kHz for basic groups or kHz for supergroups) for , , and across the multiplexed assembly. The modulator's carrier suppression minimized spectral inefficiency, though pilot tones themselves were not suppressed but used to maintain system alignment during transmission. By the late , ring modulation in declined sharply as digital (TDM) technologies, such as AT&T's systems based on (PCM), offered superior noise immunity, capacity, and cost efficiency, largely supplanting analog FDM starting in the . However, remnants persist in some rural links, where analog FDM configurations continue to support voice and in areas lacking fiber infrastructure, often as hybrid solutions bridging legacy equipment.

Limitations and Considerations

Inherent Technical Limitations

Ring modulation, as implemented in diode-based circuits, suffers from leakage due to imperfect in the modulator components, resulting in a signal appearing in the output. This leakage arises primarily from mismatches in the s forming the ring and imbalances in the input and output transformers, which prevent complete cancellation of the . The suppression ratio, a measure of this leakage, is typically in the range of 30 to 60 in practical diode ring modulators. Overmodulation distortion occurs in ring modulators when the amplitude of the modulating signal exceeds that of the carrier, leading to incomplete switching of the diodes and the introduction of unwanted harmonics in the output spectrum. In ideal multiplication, ring modulation produces only sum and difference frequencies, but non-ideal diode behavior under these conditions generates intermodulation products, distorting the sidebands and adding extraneous frequency components. This effect is exacerbated in diode ring configurations, where the hard clipping characteristic of the diodes produces bright extra harmonics, reducing the purity of the modulated signal. Dynamic range in ring modulators is inherently limited by the , which restricts the handling of weak modulating signals without degradation, and by quadrature-like imbalances that cause asymmetry between the upper and lower s. The for double-balanced ring mixers is approximately 5.5 , setting a fundamental lower bound on detectable signal levels due to and in the s. Imbalances from mismatch or asymmetry introduce even-order products, leading to unequal amplitudes and further compressing the effective , particularly at low signal levels. Bandwidth constraints in ring modulators stem from parasitic capacitances and inductances in the s and s, which limit the operable frequency range for high-frequency carriers. These parasitics introduce shifts and at elevated frequencies, degrading the switching of the and reducing the modulator's conversion beyond several hundred MHz in typical implementations. itself imposes an upper limit, as inter-winding capacitances and leakage inductances cause , confining practical operation to frequencies where component parasitics do not dominate the response.

Practical and Design Challenges

Achieving precise balance in ring modulators is essential to minimize leakage, a persistent issue arising from inherent imbalances in the . In analog -based designs, techniques such as trimming are employed to adjust for variations in forward resistances, enabling suppression levels up to 40-60 relative to the sidebands. Auto-nulling s, which introduce controlled offsets to the modulating signal port, further enhance rejection by compensating for imbalances in the ring. Temperature drift compensation is critical, as thermal variations can alter characteristics and values, leading to gradual degradation in balance; this is often addressed through dedicated compensation networks using matched s to stabilize performance across operating conditions. Component matching plays a pivotal role in maintaining modulator integrity, particularly in analog implementations where mismatches amplify carrier feedthrough and . Diodes and resistors must typically exhibit tight tolerances, such as 1% for resistors and closely matched forward voltages for diodes (e.g., Schottky types), to ensure symmetrical switching and minimize out-of-balance currents at low carrier levels. Aging of components, including degradation over time, exacerbates these issues by shifting matching parameters, potentially reducing suppression ratios by 10-20 without recalibration, necessitating periodic maintenance or selection of high-stability parts in long-term deployments. Power efficiency poses distinct challenges in both analog and digital ring modulators. Analog diode-ring configurations demand substantial drive , often +7 to +17 m, to fully switch the diodes and achieve low , resulting in higher overall consumption compared to active alternatives and limiting suitability for battery-powered systems. In realizations, low-bit-depth implementations (e.g., 8-12 bits) introduce significant quantization during signal multiplication, elevating the and degrading signal-to-noise ratios by up to 6 per bit reduction, particularly in where rounding errors accumulate. This can be mitigated through higher precision or dithering, but at the cost of increased computational overhead. Testing ring modulators focuses on verifying suppression and through established methods, while emerging tools address complexity. Spectrum analyzers are routinely used to measure leakage by injecting a single-tone modulating signal and observing residual amplitude relative to sidebands, targeting suppression better than 40 dB for practical viability. These approaches build on inherent leakage constraints by iteratively optimizing parameters via simulations.

References

  1. [1]
    Ring Modulation & Autoconvolution
    ### Summary of Ring Modulation from https://www.sfu.ca/sonic-studio-webdav/cmns/Handbook%20Tutorial/Modulation.html
  2. [2]
    Understanding How Ring Modulators Produce AM Signals
    Feb 9, 2025 · Among modulator circuits, the ring modulator stands out as one of the most effective for generating AM signals. Learn why in this article.
  3. [3]
    A Simple Guide to Modulation: Ring Mod - InSync - Sweetwater
    Jan 31, 2024 · Ring mod is an amplitude-based tool that combines two signals, outputting their sum and difference, creating metallic sounds. It's an audio ...
  4. [4]
    https://www.perfectcircuit.com/signal/ring-modulators
  5. [5]
    (PDF) Ring Modulation and Structure - Academia.edu
    Ring modulation allows simultaneous output of summed and difference frequencies from two input signals. The ring modulator's design features a diode ring, ...
  6. [6]
    [PDF] an introduction to the ring modulation application
    This final written review introduces the brief history of ring modulation application and the basic modulation principle with a mathematical formula in ...
  7. [7]
    MSP Tutorial 8: Tremolo and Ring Modulation - Max Documentation
    Multiplication of signals in the time domain is equivalent to convolution of spectra in the frequency domain.
  8. [8]
    [PDF] An analysis of transistor-based analog ring modulators - DAFX
    Sep 1, 2009 · ABSTRACT. This work analyzes analog ring modulators based on bipolar transistors, such as the EMS VCS3 and the Doepfer A-114. It is.<|control11|><|separator|>
  9. [9]
    US2025158A - Modulating system - Google Patents
    MODULATING SYSTEM Filed June 7, 1934 m/ve/vro/v F .A. COWAN Patented Dec. 24, 1935 UNITED STA MODULATING SYSTEM Frank Augustus Cowan, to American Telepho ...
  10. [10]
    Frank A. Cowan - Engineering and Technology History Wiki
    Feb 15, 2019 · Mr. Cowan won a number of patents, prominent among these are bridge- and ring-type modulators and demodulators widely used in communications ...
  11. [11]
    1941: Semiconductor diode rectifiers serve in WW II
    During WWII, semiconductor diode rectifiers were used in radar receivers to detect and convert microwave signals, using silicon and germanium. Millions were ...
  12. [12]
    Diode Modulators, April 1953 QST - RF Cafe
    Diode modulators use semiconductor diodes, not vacuum tubes, to create single-balanced bridge and ring modulator circuits. They are used in carrier telephony.
  13. [13]
    Commercial Aspects of Single-Sideband, June 1956 Radio ...
    Jun 10, 2019 · The speech signal is fed into the microphone and amplified in the speech amplifier and thence goes into the balanced modulator. Block ...
  14. [14]
    about MC1496 modulator/demodulator | Forum for Electronics
    Sep 12, 2022 · MC1496 is one of the oldest chips, which after 50 years (1972) since its first production by Motorola, is still in production. Regarding ...Missing: introduction | Show results with:introduction
  15. [15]
    Ring modulation - Wikipedia
    Ring modulation is a signal processing function, an implementation of frequency mixing, in which two signals are combined to yield an output signal.Simplified operation · History · Integrated circuit methods of... · Applications
  16. [16]
    [PDF] Software-Defined Radio for Engineers | Analog Devices
    Mar 26, 2018 · ... Modulation. 127. 4.2.1 Power Efficiency. 128. 4.2.2 Pulse Amplitude ... hybrid analog and digital designs. Here we will focus on MATLAB ...
  17. [17]
    Is Analog Gear Still Worth It in 2025? - GTZ Audio
    Oct 28, 2025 · For years, engineers have argued about this: Do you really need analog gear anymore? In 2025, the debate is louder than ever.
  18. [18]
    Dr Scientist unveils a next level Multi-Mode Ring Modulator in the ...
    Nov 29, 2023 · Dr Scientist unveils a next level Multi-Mode Ring Modulator in the same format as their fantastic Dusk Analog Filter.
  19. [19]
    [PDF] MT-080: Mixers and Modulators - Analog Devices
    An analog multiplier generally has two signal input ports, which can be called X and Y, and generates an output W that is the linear product of the voltages ...
  20. [20]
    [PDF] circuit analysis of the diode ring modulator
    Jul 22, 2015 · In this configuration the carrier signal is applied to the transformer T1 and the modulating signal to T2. The output voltage is measured over ...
  21. [21]
    [PDF] digital simulation of the diode ring modulator for musical
    It consists of four diodes and two center-tapped transformers. The basic idea behind the circuit is that when the carrier voltage uC is positive, diodes D1 and ...
  22. [22]
    [PDF] MSK 003 Passive ring modulator
    Feb 7, 2015 · Gather together all the parts you will need. Each ring modulator requires four diodes (see comments earlier about choosing the diodes), three ...<|control11|><|separator|>
  23. [23]
    Digital Signal Processing (SOS Nov 89) - mu:zines
    The basic principle of ring modulation is extremely simple - the output is generated by the multiplication of two input signals, and in digital signal ...
  24. [24]
    5: Continuous-time Convolution Anti-aliasing for Ring Modulation
    Sep 28, 2025 · In order to anti-alias an effect with this technique, we must first consider the continuous version of an effect. Then, we create a digital ...
  25. [25]
    [PDF] A Hilbert-Transformer Frequency Shifter for Audio - DAFX
    Ring modulation is a generalization of double-sideband suppressed-carrier modulation, and ... the Hilbert Transform of the signal, which is defined in the ...
  26. [26]
    [PDF] FPGA Implementation of Digital Modulation Techniques BPSK and ...
    The modulator was coded in Verilog HDL and was implemented on Spartan-3E FPGA with all the two above designs. The Xilinx synthesis tool which generates ...
  27. [27]
    Fixed-Point vs. Floating-Point Digital Signal Processing
    Dec 2, 2015 · As such, floating-point processing yields much greater precision than fixed-point processing, distinguishing floating-point processors as the ...
  28. [28]
    Live Audio Effect Reference — Ableton Reference Manual Version 12
    Echo is a modulation delay effect that lets you set the delay time on two independent delay lines, while giving you control over envelope and filter modulation.
  29. [29]
    Ringotron - App Store - Apple
    Ringotron allows taming the strong transformational effects of traditional ring modulation, opening up a wider range of possibilities in sound design and audio ...
  30. [30]
    Activity: Diode Ring Modulator - ADALM2000 [Analog Devices Wiki]
    Feb 7, 2022 · The objective of this activity is to describe the operation of a diode ring mixer, to identify some of its applications, and to learn the basics.
  31. [31]
    Analog Communication - DSBSC Modulators - Tutorials Point
    Ring Modulator. In this diagram, the four diodes D1,D2,D3 and D4 are connected in the ring structure. Hence, this modulator is called as the ring modulator.
  32. [32]
    [PDF] Lecture 6: Modulators, Receivers, AM, and SSB
    Oct 5, 2021 · DSB-SC vs. AM. DSB-SC modulated signals undergo phase reversal when m(t) changes sign. It is difficult to extract carrier from received ...
  33. [33]
    [PDF] PRODUCT DETECTOR BALANCED (DE-)MODULATOR - QSL.net
    But in a receiver or transmitter, we frequently use a “mixer” that actually creates these sum and difference frequencies through a desired non-linear action ...
  34. [34]
    Communications Receivers. Detector Circuits. - Angelfire
    Jan 27, 2016 · The diode ring modulator is doubly balanced which means that both input signals are canceled out and only the product appears in the output.<|separator|>
  35. [35]
    [PDF] RECOMMENDATION ITU-R BS.640-3 - Single sideband (SSB ...
    ITU-R BS.640-3 specifies SSB for HF broadcasting, with audio bandwidth up to 4.5 kHz, 5 kHz channel spacing, 12 dB carrier reduction, and 4 kHz receiver ...Missing: shortwave radio
  36. [36]
    uBITX V6 - HF Signals
    It is a compact, single board design that covers the entire HF range with a few minor trade-offs. This rig has been in regular use on forty and twenty meters ...
  37. [37]
    Software Defined Radio – The Future of Amateur Radio?
    Feb 19, 2016 · We are now to the point where it is possible to build an SDR for Amateur Radio applications that can directly sample RF at frequencies as high as 150 MHz.
  38. [38]
    Ring Modulation 101: Creating Super Unique Sounds + Tips
    Feb 23, 2025 · Ring modulation combines an input signal with a modulator signal, creating a new output based on the sum and difference of their frequencies, ...Missing: definition | Show results with:definition
  39. [39]
    EMS VCS3 [Retrozone] - Sound On Sound
    Ring modulation on the VCS3 is particularly good at producing clangorous bell‑like tones (akin to the DX7), which is often due to the fact that although the ...
  40. [40]
    May 17 1965, Moog introduces the first analog synthesizer.
    May 17, 2012 · The Moog Company pioneered the commercial manufacture of modular voltage-controlled analog synthesizer systems in the early 1950s.
  41. [41]
    Vintage music tech icons: EMS VCS3 - MusicRadar
    Oct 28, 2021 · England's first commercial synthesizer, EMS' VCS3 was released in 1969. EMS (Electronic Music Studios) had its genesis in the personal ...<|control11|><|separator|>
  42. [42]
    Ring Thing | Single Sideband Modulator - Electro-Harmonix
    From metallic sweeps to subtle color changes to unique and limitless modulations, it will become your sonic dream machine!
  43. [43]
    Hey, what's that sound: Ring modulators | Electronic music
    Nov 9, 2009 · Ring modulation became popular in early pre-synthesiser electronic music as oscillators were originally only capable of generating standard ...
  44. [44]
    How Modulation Effects Will Improve Your Music - Icon Collective
    Increasing the modulator frequency creates a faster vibrato, making the signal audible. At a certain point, you stop hearing vibrato and hear new frequencies ...
  45. [45]
    [PDF] ENGiNEERiNG ANd OPERATioNS iN TilE BELL SySTEM
    The first edition of this book, published in 1977, presented a comprehensive view of the Bell System as seen from AT&T Bell Labora- tories.
  46. [46]
    Second-order ring modulator. Calculations of losses and some ...
    The second-order ring modulator takes its output at a ... Second-order ring modulator. Calculations of ... carrier telephony · modulation · rectification ...
  47. [47]
    [PDF] Fascicle III.2 - CCITT (Geneva, 1980)
    Group-delay distortion of the through-group filter. In the case of through-connection of a group in the basic frequency band 60-108 kHz, it is recommended.
  48. [48]
    https://allenluker.wordpress.com/from-fdm-to-tdm-in-depth/
  49. [49]
    [PDF] Single Sideband Radio Communications
    ... Carrier Telephony System . . . 1-2. Essential Components in a Modern Carrier ... Ring Modulator . . Carrier Current Paths When Polarity Reverses ...
  50. [50]
    Legacy Telephony FDM to TDM (PCM/DS1-framing-coding and ...
    In the late 1950's and early 60's Bell engineers found a way of converting signals to a digital format from analog signals for transmission, with the digital ...
  51. [51]
    [PDF] Technical Report Rural Microwave Radio Final Report
    The transmission of multiplexed telephony channels has traditionally been performed using analog techniques due to the simple realization of. analog systems ...Missing: persists | Show results with:persists
  52. [52]
    Circuit for improving carrier rejection in a balanced modulator
    Typical leakage values in such devices are in the range of 30 to 50 dB isolation. Accordingly, a +7 dBm (5 mW) signal applied to the carrier signal port 10 will ...
  53. [53]
    https://www.eevblog.com/forum/rf-microwave/toroid-selection-for-diode-ring-mixer/
  54. [54]
    Sources of intermodulation in diode-ring mixers - IET Digital Library
    Intermodulation is known to arise in diode-ring mixers due to non-linearity in the diode switches, and also due to the interference by signal voltages with ...Missing: overmodulation | Show results with:overmodulation
  55. [55]
    Toroid selection for diode ring mixer - EEVblog
    Aug 26, 2018 · To obtain isolation, follow it with a 1:1 isolation transformer. An isolation transformer cannot have unlimited bandwidth, sadly, but we can ...Missing: modulator | Show results with:modulator
  56. [56]
    https://www.eurasip.org/Proceedings/Eusipco/Eusipco2016/papers/1570251794.pdf
  57. [57]
    [PDF] W. J. Lindsay H. W. Estry R. L. Miller February 1967
    D9, DlO9 and Dll provide circuit temperature compensation. characteristic ... diode ring modulator, modulator driver, an AC (carrier) amplifier, and a.
  58. [58]
    [PDF] Analysis of the Quantization Error in Digital Multipliers with Small ...
    This additive noise source model has proven to be successful for the analysis of fixed point arithmetic when the wordlength after quantization is not too small ...Missing: ring | Show results with:ring
  59. [59]
    Machine Learning based calibration SDR in Digital Twin application
    This paper presents the evaluation of a laboratory prototype based on low-cost commercial software-defined radios equipment.Missing: modulator | Show results with:modulator