Table of Contents
Introduction
Anyone working in RF engineering who needs to test, characterize, or qualify components, subassemblies, or complete wireless systems eventually faces a fundamental decision: microwave signal generator (MSG) or vector signal generator (VSG)? Both instrument categories generate high-frequency signals, yet they differ fundamentally in architecture, signal versatility, and application field.
At its core, a signal generator is any test instrument that produces a defined electrical signal — usually a radio-frequency signal — with precisely adjustable parameters such as frequency, amplitude, and modulation. In practice, however, not every signal generator is suited to every task. An RF engineer who needs precise pulse sequences with nanosecond resolution for radar work has very different requirements than a 5G chip developer who needs to generate a standard-compliant OFDM signal with minimal EVM.
Why does the choice of instrument matter so much? Three factors largely determine the quality of an RF measurement:
- Spectral purity – how clean is the generated signal, free of unwanted spurious lines and phase noise?
- Modulation quality – how accurately does a digitally modulated signal match the theoretical constellation?
- Frequency coverage – does the instrument actually cover the operating frequency of the device under test (DUT)?
In this guide, we walk through both instrument families in detail, explain the underlying technologies, and provide a concrete decision-making aid at the end. Both families — MSG and VSG alike — share a common foundation that is often underestimated: the clock source, the internal reference that determines the frequency accuracy and noise performance of every signal generated. Let’s start there.
💡 Note: At the end of this article you’ll find our interactive online selection tool, which automatically recommends the right instrument type and optimal configuration based on your requirements.
1. The Clock Source – The Heart of Every Signal Generator
1.1 What Is a Clock Source?
Every signal generator — whether MSG or VSG — relies on an internal reference oscillator that serves as the time and frequency base for every signal the instrument produces. This clock source determines three central properties:
- Frequency accuracy – how precisely does the set frequency match the actual output frequency?
- Phase noise – how strongly does the spectral line „smear“ due to short-term jitter?
- Short- and long-term stability – how much does the frequency drift over seconds, hours, or years?
Virtually all professional instruments offer, in addition to the internal reference, an external reference input, typically at 10 MHz. This allows multiple instruments in a test setup to be synchronized, or a single instrument to be locked to a higher-order, highly accurate reference (e.g., a lab-grade rubidium standard). The relevant figures of merit are relative frequency stability (dimensionless, e.g., 1 × 10⁻⁹) and Allan deviation, a statistical measure used to characterize frequency stability across different averaging times.
1.2 Overview of Oscillator Types
Depending on the application and budget, different oscillator technologies are used. The table below gives an overview of the most common types:
| Oscillator Type | Stability (short-term) | Stability (long-term) | Phase Noise (typical) | Cost | Learning Resource |
|---|---|---|---|---|---|
| TCXO | ~10⁻⁷ | ~10⁻⁶ | medium | low | Wikipedia: TCXO |
| OCXO | ~10⁻⁹ | ~10⁻⁸ | very good | medium | NIST: Oscillator Standards |
| Rubidium | ~10⁻¹¹ | ~10⁻¹⁰ | excellent | high | PTB Berlin: Atomic Clocks |
| Cs Atomic Clock / H-Maser | Primary standard | Primary standard | — | very high | BIPM: Time Standards |
1.3 TCXO – Temperature Compensated Crystal Oscillator
The TCXO is the most cost-effective and widely used reference solution. Its operating principle relies on active voltage correction: a temperature sensor continuously measures the ambient temperature of the crystal, and a compensation circuit corrects the resulting frequency deviation in real time. Since quartz crystals exhibit a characteristic but predictable frequency-versus-temperature curve, this effect can be well compensated — though never fully eliminated.
TCXOs are typically found in entry-level and mid-range instruments, where cost and size matter more than extreme frequency stability. For many everyday measurements — such as basic filter characterization or functional tests — the achievable accuracy is entirely sufficient.
In-depth teaching material on crystal oscillators is available from, among others, the Technical University of Munich and MIT OpenCourseWare.
1.4 OCXO – Oven Controlled Crystal Oscillator
The OCXO takes things a step further: instead of merely compensating for temperature deviation, the crystal is operated inside an actively heated, thermally insulated „oven“ at a constant temperature — typically around 75 °C. Because this temperature lies above normal ambient conditions, it can be precisely regulated regardless of external fluctuations. The result: short-term stability in the range of 10⁻⁹ to 10⁻¹⁰, and long-term stability around 10⁻⁸.
The OCXO is the de facto standard reference in professional test and measurement equipment. It is found in virtually every established lab-grade signal generator — from Rohde & Schwarz to Keysight to Anritsu. The only drawback: the heated oven requires some warm-up time after power-on before the specified stability is reached, along with continuous, if modest, heating power.
University resources for further reading: University of Stuttgart – RF Engineering, Stanford Electrical Engineering, and Tsinghua University – RF Research.
1.5 Rubidium Oscillator (RbXO)
For applications where even OCXO-level stability is not sufficient, rubidium oscillators come into play. Their operating principle exploits the atomic hyperfine transition of rubidium-87 at exactly 6.834 GHz as an absolute frequency reference. A quartz oscillator is continuously steered (phase-locked) against this atomic transition frequency.
The result is short-term stability of 10⁻¹¹ to 10⁻¹² — significantly better than any OCXO. Over very long time scales (days to weeks), the rubidium reference also clearly outperforms the OCXO, since it is not subject to crystal aging but instead locked to a physically fixed atomic transition. Rubidium references are typically found in top-tier instruments as well as in time-standard laboratories.
Further resources from international metrology and research institutes: PTB Berlin, NIST, Observatoire de Paris / SYRTE, INRIM Torino, IIT Bombay, National Time Service Center China, and TU Wien.
1.6 Cesium Atomic Clock and Hydrogen Maser
At the top of the accuracy hierarchy sit cesium atomic clocks and hydrogen masers. They are considered primary standards — the cesium atomic clock even defines the SI second itself. These devices are not used in commercial signal generators; they are found exclusively in calibration laboratories and national metrology institutes, where they serve as the reference for traceability of all other time and frequency standards. Further information is available from PTB, NIST, and the BIPM.
2. Microwave Signal Generators (MSG)
Further background: Wikipedia: Signal Generator · Wikipedia: Sweep Generator
2.1 Definition and Overview
A microwave signal generator (MSG) is specialized in producing highly pure, continuous or pulsed RF signals across a very wide frequency range — typically from 100 kHz to 67 GHz, extendable in top-tier models to beyond 110 GHz. The architecture of an MSG essentially follows a clear signal path: a frequency synthesizer generates the carrier, a downstream power stage amplifies the signal to the required level, a precision attenuator sets the exact output power, and finally the signal exits the instrument through the RF output.
MSGs are used wherever maximum spectral purity and the widest frequency coverage are required: in radar technology, satellite communication systems, component characterization (amplifiers, filters, mixers), EMC test engineering, and as a stimulus source for testing spectrum analyzers and receivers.
2.2 Signal Generation – Techniques and Principles
Inside an MSG, different synthesis techniques are used, differing in resolution, switching speed, and achievable frequency range:
| Technique | Principle | Strengths | Typical Application | Resource |
|---|---|---|---|---|
| PLL (Phase-Locked Loop) | Feedback loop locked to a reference | Low spurious content | Standard in MSGs | IEEE Xplore: PLL |
| YIG Oscillator | Yttrium iron garnet, magnetically tunable | Very wide frequency range | Broadband MSGs | Wikipedia: YIG |
| DDS (Direct Digital Synthesis) | Digital waveform table + DAC | Fine resolution, fast tuning | Arbitrary and pulse generators | IEEE: DDS Tutorial |
| Fractional-N PLL | Non-integer division ratio | Sub-Hz frequency resolution | Ultra-precise MSGs | Wikipedia: Fractional-N PLL |
In practice, modern MSGs typically combine several of these principles: a PLL-based core synthesizer establishes the fundamental frequency, a YIG oscillator covers the required broadband range, and a DDS stage provides fine, fast frequency steps.
2.3 Signal Types and Modulation Formats
2.3.1 CW Signal (Continuous Wave)
The simplest and most fundamental signal an MSG produces is a pure sine wave at a fixed frequency and amplitude — the CW signal. It serves as the basis for numerous measurements: determining the gain of an amplifier, measuring the insertion loss of a filter, or calibrating power sensors.
2.3.2 Analog Modulation
| Modulation | Description | Resource |
|---|---|---|
| AM | Amplitude Modulation | Wikipedia: AM |
| FM | Frequency Modulation | Wikipedia: FM |
| PM | Phase Modulation | Wikipedia: PM |
| Pulse ON/OFF | Switching the RF carrier on and off | — |
2.3.3 Pulse Generation and Pulse Parameters
For radar applications and the characterization of pulsed systems, precise pulse generation is a core capability of the MSG. The following parameters are central:
- Pulse Width (PW): duration of the RF burst, typically ranging from nanoseconds to milliseconds
- Pulse Repetition Frequency (PRF): number of pulses per second
- Dwell Time: time spent at a given frequency, relevant in list or step mode
- Duty Cycle: ratio of pulse width to total period
- Pulse Trains and Sequences: complex, realistic emulation of radar signals with varying pulse parameters
These capabilities are essential for radar pulse characterization, testing TR modules (transmit/receive modules in phased-array systems), and simulating Doppler-shifted target returns. Further reading: Wikipedia: Pulse Radar.
2.3.4 Sweep Mode
In sweep mode, the MSG continuously or stepwise (step sweep) traverses a defined frequency or power range. This mode of operation is ideal for characterizing the frequency response of filters as well as for antenna measurements. See also: Wikipedia: Sweep Generator.
2.3.5 List Mode / Step Mode
In list or step mode, the generator jumps between predefined frequency and power breakpoints, with the dwell time at each breakpoint individually configurable. This enables complex, repeatable test sequences, for example the automated characterization of multiple operating points of a DUT.
2.4 Phase Noise – Definition, Importance, and Top Performance
Phase noise is arguably the most important — yet also one of the most misunderstood — figures of merit of a signal generator. Simply put, it describes the short-term frequency instability of an oscillator, which appears in the frequency spectrum as sideband-shaped noise surrounding the actual carrier line. A „perfect“ oscillator would appear as an infinitely narrow line in the spectrum — in reality, phase noise „smears“ this line into a bell-shaped curve around the carrier.
The common figure of merit is the single-sideband phase noise (SSB phase noise) ℒ(f), expressed in dBc/Hz (decibels relative to the carrier, per Hertz of bandwidth) at a given frequency offset from the carrier. For a mathematically rigorous treatment of the topic — including measurement methods and definitions — IEEE Std 1139-2022 is recommended, the international standard for characterizing oscillator phase noise.
Why is phase noise so critical in practice?
- Radar: Phase noise limits the achievable Doppler resolution and, therefore, the ability to distinguish slow-moving targets from ground clutter.
- Receiver testing: The phase noise of the stimulus generator directly degrades the measured noise figure of the receiver under test.
- High-data-rate communications: Phase noise increases Error Vector Magnitude (EVM) and thereby limits the maximum usable modulation order (e.g., 256-QAM instead of 1024-QAM).
To provide a sense of typical values, here is a comparison table (referenced to a 1 GHz carrier at a 10 kHz offset):
| Instrument Class | Phase Noise (typ.) | Example Instruments (various manufacturers) |
|---|---|---|
| Basic MSG (TCXO) | ~ −115 dBc/Hz | Entry-level class |
| Professional MSG (OCXO) | ~ −130 dBc/Hz | R&S SMA100A, Keysight N5173B, Anritsu MG3690C |
| Ultra-low-noise MSG (OCXO opt.) | ~ −143 dBc/Hz | R&S SMA100B (Ultra-Low Phase Noise Option) |
| MSG with Rb reference | ~ −150 dBc/Hz | MSG combined with an external Rb reference |
How important phase noise actually is for your application depends strongly on the intended use: a radar engineer weighs it fundamentally differently than an engineer simply looking to characterize a filter. The following table maps the key MSG properties to their typical use cases.
2.5 Applications and Selection Criteria for MSGs
| Property | Why It Matters | Typical Use Case |
|---|---|---|
| Phase noise (SSB) | Spectral purity, Doppler resolution | Radar, electronic warfare, receiver noise figure |
| Frequency range (max. frequency) | Coverage of DUT operating frequency | mmWave components, 5G FR2, satellite communications |
| Pulse parameters (PW, PRF, dwell) | Radar pulse emulation | Radar module testing, TR-switch characterization |
| Output power & range | P1dB and IP3 measurements | Amplifier characterization |
| Frequency accuracy (OCXO/Rb) | Calibration traceability | Reference calibration, atomic clock comparison |
| Sweep speed | Fast filter/antenna scans | RF component development |
3. Vector Signal Generators (VSG)
Further background: Wikipedia: Vector Signal Generator · NI: VSG Overview
3.1 Definition and Overview
A vector signal generator (VSG) differs from an MSG through one key additional element: an integrated I/Q modulator together with a baseband generator. While an MSG „only“ generates the carrier frequency with simple analog modulation, a VSG can modulate arbitrary, digitally computed baseband signals onto a carrier — the foundation of every modern digital communications technology.
The typical frequency range of a VSG extends up to 44 GHz, with some top-tier models reaching 67 GHz natively; for sub-THz applications, external upconverters are used. Historically, the introduction of digital mobile standards such as GSM in the 1990s was the decisive driver behind the development of this instrument category. Today, VSGs are indispensable in mobile communications R&D, chip testing, IoT development, and standards conformance testing.
3.2 Signal Generation – I/Q Modulation as the Core Principle
The signal path of a VSG follows a clearly structured sequence:
- Baseband generator (DSP): symbol mapping according to the chosen modulation format, filtering (typically using a root-raised-cosine filter for bandwidth limiting), and generation of the I/Q waveform
- DAC: digital-to-analog conversion of the I/Q signal
- I/Q modulator: multiplication of the carrier frequency with the I/Q baseband signal to produce the modulated RF signal
- Upconversion and RF output
The most important figure of merit for a VSG is Error Vector Magnitude (EVM) — a measure of how far the actually generated symbol vectors deviate from their theoretically ideal position in the constellation. Further reading: Wikipedia: EVM. Another key parameter is modulation bandwidth, which determines the maximum signal bandwidth that can be generated — for 5G NR FR1, for example, up to 400 MHz is required. Detailed technical background can be found in application notes from major test equipment manufacturers (Rohde & Schwarz, Keysight).
3.3 Analog Modulation in the VSG
Classic analog modulation types such as AM, FM, and PM are also available in the VSG — implemented digitally, however. The advantage: these modulations can be configured entirely in software and freely combined with digital waveforms, for example to simulate realistic interference scenarios.
3.4 Digital Modulation Formats
The core strength of a VSG is its ability to generate virtually any digital modulation format. The table below provides an overview of the most important formats:
| Modulation | Description | Bits/Symbol | Typical Use | Resource |
|---|---|---|---|---|
| ASK | Amplitude-shift keying | 1 (OOK) | RFID, optical | Wikipedia: ASK |
| FSK | Frequency-shift keying | 1 | IoT, DECT | Wikipedia: FSK |
| MSK/GMSK | Minimum/Gaussian FSK | 1 | GSM, Bluetooth | Wikipedia: GMSK |
| BPSK | Binary phase-shift keying | 1 | GPS, DVB | Wikipedia: PSK |
| QPSK | Quadrature PSK | 2 | UMTS, LTE, 5G | Wikipedia: QPSK |
| 8PSK | 8-level PSK | 3 | EDGE, DVB-S | — |
| 16-QAM | 16-level QAM | 4 | LTE, Wi-Fi | Wikipedia: QAM |
| 64-QAM | 64-level QAM | 6 | LTE-A, Wi-Fi 5 | — |
| 256-QAM | 256-level QAM | 8 | Wi-Fi 6, 5G NR | — |
| 1024-QAM | 1024-level QAM | 10 | Wi-Fi 6E, 5G NR Advanced | — |
| 4096-QAM | 4096-level QAM | 12 | Wi-Fi 7 (802.11be) | IEEE 802.11be |
| OFDM | Multi-carrier modulation | variable | LTE, 5G, Wi-Fi | Wikipedia: OFDM |
| SC-FDMA | Single-carrier FDMA | variable | LTE uplink | 3GPP: LTE UL |
| APSK | Amplitude + phase shift keying | variable | DVB-S2 | ETSI EN 302 307 |
A clear trend emerges: with every new mobile and Wi-Fi generation, modulation order increases — from QPSK through 64-QAM up to 4096-QAM in Wi-Fi 7. Higher modulation orders carry more bits per symbol, but they also place dramatically higher demands on the EVM and phase noise performance of the generating VSG.
3.5 Communication Standards – Complete Overview
A key advantage of modern VSGs is their software-defined flexibility: a single instrument can — depending on installed options — generate virtually any relevant mobile, Wi-Fi, or IoT standard.
Mobile Communication Standards
| Standard | Generation | Modulation | Bandwidth | Standards Body | Link |
|---|---|---|---|---|---|
| GSM | 2G | GMSK | 200 kHz | 3GPP TS 45.xxx | 3GPP |
| GPRS/EDGE | 2.5G | 8PSK | 200 kHz | 3GPP | 3GPP |
| UMTS/WCDMA | 3G | QPSK | 5 MHz | 3GPP TS 25.xxx | 3GPP TS 25 |
| HSPA / HSPA+ | 3.5G | 16-QAM | 5–20 MHz | 3GPP | 3GPP |
| TD-SCDMA | 3G (China) | QPSK | 1.6 MHz | 3GPP TS 25.xxx | 3GPP |
| LTE (4G) | 4G | QPSK–64-QAM / OFDM | up to 20 MHz | 3GPP TS 36.xxx | 3GPP TS 36 |
| LTE-A / LTE-A Pro | 4.5G | 256-QAM | up to 100 MHz (CA) | 3GPP Rel. 12–14 | 3GPP Releases |
| 5G NR (FR1) | 5G | up to 256-QAM / OFDM | up to 100 MHz | 3GPP TS 38.xxx | 3GPP TS 38 |
| 5G NR (FR2 / mmWave) | 5G | up to 256-QAM | up to 400 MHz | 3GPP TS 38.xxx | 3GPP TS 38 |
| 5G NR Advanced (R18+) | 5G Adv. | up to 1024-QAM | 400 MHz+ | 3GPP Rel. 18 | 3GPP Rel. 18 |
| 6G (IMT-2030) | 6G (research) | TBD (sub-THz) | TBD (GHz-class) | ITU-R IMT-2030 | ITU-R IMT-2030 |
Wi-Fi / WLAN Standards
| Standard | Wi-Fi Gen. | Modulation (max.) | Max. Bandwidth | Standards Body | Link |
|---|---|---|---|---|---|
| 802.11a/b/g | Wi-Fi 1–3 | 64-QAM / OFDM | 20 MHz | IEEE SA | IEEE 802.11 |
| 802.11n | Wi-Fi 4 | 64-QAM / OFDM | 40 MHz | IEEE SA | IEEE 802.11n |
| 802.11ac | Wi-Fi 5 | 256-QAM / OFDM | 160 MHz | IEEE SA | IEEE 802.11ac |
| 802.11ax | Wi-Fi 6/6E | 1024-QAM / OFDMA | 160 MHz | IEEE SA | IEEE 802.11ax |
| 802.11be | Wi-Fi 7 | 4096-QAM / OFDMA | 320 MHz | IEEE SA | IEEE 802.11be |
Other Standards (Bluetooth, Satellite Communications, IoT)
| Standard | Family | Modulation | Standards Body | Link |
|---|---|---|---|---|
| Bluetooth Classic | BT | GFSK / π/4-DQPSK | Bluetooth SIG | bluetooth.com |
| Bluetooth Low Energy | BLE | GFSK | Bluetooth SIG | bluetooth.com |
| DVB-S2 / DVB-S2X | Satellite | QPSK–32APSK | ETSI | ETSI EN 302 307 |
| DVB-T2 | Terrestrial TV | 256-QAM / OFDM | ETSI | ETSI EN 302 755 |
| NB-IoT | IoT/LPWAN | QPSK / SC-FDMA | 3GPP | 3GPP |
| LTE-M / eMTC | IoT/LPWAN | 16-QAM / OFDM | 3GPP | 3GPP |
| Zigbee (802.15.4) | IoT | O-QPSK | IEEE SA | IEEE 802.15.4 |
| Z-Wave | IoT | GFSK / OFDM | ITU-T G.9959 | ITU-T G.9959 |
| IEEE 802.11p / DSRC | V2X | OFDM | IEEE SA | IEEE 802.11p |
| DECT | Cordless | GFSK | ETSI | ETSI EN 300 175 |
3.6 6G – Vector Signal Generators in Research
6G is currently still in an intensive research phase, guided by the ITU-R IMT-2030 framework. In the lower and mid frequency ranges (FR1/FR3), classic VSGs can already be used for signal generation today. For sub-THz and H-band applications, however, the VSG generates only an IF signal (intermediate frequency), which is then upconverted into the target frequency range via an external upconverter.
Early research demonstrations already point to the potential: Fraunhofer HHI, for example, has demonstrated transmissions in the 300 GHz range, while Rohde & Schwarz offers the SFI100A, a signal generation system for the W- and D-band range. Another active research field is Reconfigurable Intelligent Surfaces (RIS), which serve as a new test field for VSG-based test setups.
Looking ahead: initial 6G standardization is expected around 2029–2030, under 3GPP Release 21 and beyond. Until then, signal generation for 6G research purposes remains the domain of specialized, often modularly extended VSG systems.
3.7 Applications and Selection Criteria for VSGs
| Property | Why It Matters | Typical Use Case |
|---|---|---|
| EVM | Modulation quality, chip verification | Digital demodulator testing, PA linearity testing |
| Modulation bandwidth | Coverage of signal bandwidth | 5G NR (100/400 MHz), Wi-Fi 7 (320 MHz) |
| Standards coverage | Conformance testing (GCF, PTCRB, Wi-Fi Alliance) | Mobile device qualification |
| Waveform memory (RAM) | Long sequences / replay | Realistic fading simulation |
| MIMO capability (multi-channel) | MIMO verification | 5G NR MIMO, Wi-Fi 6/7 MIMO |
| I/Q pulse width | Temporal resolution of digital bursts | Protocol stack testing |
| Phase noise (VSG) | EVM floor at high modulation orders | 5G NR 256-QAM, Wi-Fi 7 4096-QAM |
4. Direct Comparison: MSG vs. VSG
| Feature | Microwave Signal Generator (MSG) | Vector Signal Generator (VSG) |
|---|---|---|
| Phase noise | ✅ Top-tier (down to −150 dBc/Hz) | ✅ Very good (down to −140 dBc/Hz) |
| Max. frequency | ✅ Up to 110 GHz+ (native) | ⚠️ Typ. up to 44 GHz (67 GHz optional) |
| I/Q modulation | ❌ Not integrated (external I/Q modulator required) | ✅ Fully integrated |
| Digital standards (2G–6G) | ❌ No | ✅ Full coverage |
| Pulse control | ✅ High precision (ps resolution) | ⚠️ Limited |
| Sweep operation | ✅ Native, very fast | ⚠️ Restricted |
| Modulation bandwidth | ⚠️ Limited (typ. up to 40 MHz) | ✅ Up to 2 GHz (optional) |
| Typical applications | Radar, satellite comms, EMC, component testing | Mobile R&D, chip testing, IoT, conformance |
| Price level | Medium–very high | Medium–high |
The table makes it clear: there is no universally „better“ instrument category — the right choice depends entirely on your specific application. An MSG excels in spectral purity, frequency coverage, and precise pulse control; a VSG plays to its strengths in digital modulation quality and standards conformance.
5. Decision Guide – Which Instrument for Which Task?
5.1 Decision Tree
The diagram below guides you to the right recommendation through four simple questions:
Note for users with a Mermaid plugin: the decision tree is also available as Mermaid code and can be provided separately if your WordPress installation uses a Mermaid rendering plugin.
5.2 Quick Decision Matrix (Text Version)
- Do you need digital communication standards (2G–6G, Wi-Fi, Bluetooth)? → If yes, you need a VSG in any case.
- Do you need a modulation bandwidth greater than 40 MHz (e.g., 5G NR, Wi-Fi 6/7)? → If yes, choose a wideband VSG.
- Do you need precise pulse modulation for radar or EW applications? → If yes, an MSG with high-precision pulse control is the right choice.
- Do you need frequencies above 40 GHz (mmWave)? → If yes, choose an MSG with mmWave extension.
- Is ultra-low phase noise critical for your application (e.g., reference calibration, high-resolution radar)? → If yes, choose an MSG with an ultra-low phase noise option, ideally combined with a rubidium reference.
6. Conclusion
The choice between a microwave signal generator and a vector signal generator ultimately comes down to the application: an MSG is the right choice wherever maximum spectral purity, the widest frequency coverage, and precise pulse control are required — for example in radar, satellite communications, and component testing. A VSG, on the other hand, plays to its strengths in generating digitally modulated signals compliant with current communication standards — from GSM to 5G NR Advanced and, prospectively, 6G.
Interesting is the growing convergence of both worlds: modern flagship instruments such as the Rohde & Schwarz SMW200A with an optional 67 GHz extension already combine many properties of both categories in a single system. For most applications, however, the clear mapping — MSG for spectral purity and high frequencies, VSG for digital communications and standards conformance — remains the practical starting point for instrument selection.
Not sure which generator is optimal for your application?
Our free online configuration tool analyzes your requirements and automatically recommends the right instrument type, the appropriate clock source, and the optimal configuration — in just a few clicks.