Rohde & Schwarz SMIQ04B 300KHz-4.4GHz Synthesised Vector Signal Generator

The Rohde & Schwarz SMIQ04B is a synthesized vector signal generator spanning 300 kHz to 4.4 GHz, engineered to produce complex modulated signals for communication system development, type-approval testing, and production environments. Built on digital signal processor technology, it delivers high-precision digital modulation at high bit rates across multiple standards without mode restrictions, while simultaneously supporting analog modulation including AM, FM, phase, and pulse modes. The instrument combines flexible I/Q modulation with exceptional spectral purity and fast frequency switching, making it suitable for RF component characterization and multistandard signal synthesis.

Technical Specifications

• Frequency range: 300 kHz to 4.4 GHz


• Frequency resolution: 0.1 Hz or 100.0 mHz


• Frequency switching time: 15 ms typical (< 3 ms without attenuator switching)


• Frequency hopping: 500 µs


• Time base stability: 0.000001 /yr


• External reference: 16 MHz input (1 MHz to 16 MHz in 1 MHz steps) Output Characteristics


• Power range: −140 dBm to +13 dBm PEP


• Power resolution: 0.1 dB (0.01 dB in CW/FM/phase/auto attenuator modes)


• Output impedance: 50 Ohm


• VSWR: < 2 Spectral Purity (CW)


• Single-sideband noise: −116 to −126 dBc/Hz


• Broadband noise (20 MHz–450 MHz): < −136 dBc (−142 dBc typ.)


• Broadband noise (450 MHz–3040 MHz): < −138 dBc (−144 dBc typ.)


• Harmonic content: −30 dBc; non-harmonics: −60 dBc

Key Features

• High-grade I/Q modulator standard; minimizes error vector magnitude and intermodulation


• Digital modulation: PSK, QAM, FSK, ASK, MSK without bit-rate limitations


• Analog modulation: AM, FM, phase, pulse


• Vector and wideband AM modes


• Fine frequency resolution (0.1 Hz) for precision tuning

Typical Applications

• Multistandard transceiver development and validation


• Component characterization (amplifiers, filters, mixers)


• Type-approval testing for wireless standards


• Production signal synthesis across IF and RF bands