Description

Key facts
  • Automatic envelope voltage adaptation enables power sweeps with automatic recalculation of the envelope waveform
  • Generation of RF and envelope waveform out of one box, no extra hardware is needed for envelope calculation
  • Realtime envelope calculation from current I/Q signal, any signal configuration changes are effective immediately
  • Fully synchronous envelope and RF waveform with adjustable delay (±1?s, 1 ps resolution)
  • Realtime envelope shaping with flexible shaping functions (i.e. linear, from table, polynomial, detroughing)
  • Realtime envelope generation for nearly all communications standards or use of any customer-specific I/Q (ARB) waveform
  • High-performance analog outputs deliver envelope waveforms with best spectral purity

Brief description Envelope tracking is a technique to increase power amplifier (PA) efficiency by modulating the DC supply voltage with the envelope of the I/Q signal. Testing and verifying the performance of DC modulators and envelope tracking power amplifiers (ETPA) poses a number of challenges for T&M equipment. The envelope and the RF waveform applied to the PA must be perfectly synchronized. Envelope shaping is applied to tune the PA for best efficiency or linearity. For power sweeps and PA dynamic range tests, automatic recalculation of the envelope waveform is required. The R&S®SMW-K540 envelope tracking option meets all of these challenges. It generates the envelope of any I/Q data in realtime and outputs it via the generator's analog interfaces with best spectral purity. Since the RF and baseband envelope waveforms are generated within the same instrument, no extra cabling is needed to synchronize the two waveforms and no added jitter occurs, yielding 100 % repeatability. The RF to envelope waveform delay can be adjusted in realtime with picosecond resolution. The R&S®SMW-K540 option also provides several envelope shaping functions (i.e. table, polynomial, detroughing). A unique feature of R&S®SMW-K540 is automatic envelope voltage adaptation. This simplifies the test setup and saves designers time-consuming manual adjustments for different power levels.''