The Varian CPI VZC-6962-D6A3 is a high-power traveling wave tube amplifier (TWTA) engineered for C-band satellite earth station uplink operations. It delivers 750 W minimum output power (58.75 dBm) at the TWT output, with 650 W minimum (58.13 dBm) at the flange. The unit combines high gain with exceptional stability, making it suitable for fixed terminals, fly-away systems, and digital satellite news gathering vehicles where compact size and power efficiency are critical.
Technical Specifications
Frequency & Gain
• Frequency range: 5.850 to 6.650 GHz (VZC-6967AM baseline; extended variants to 7.075 GHz available)
• Bandwidth: 800 MHz
• Gain at rated power: 75 dB minimum, 88 dB maximum
• Gain at small signal: 78 dB minimum, 90 dB maximum
• Small signal gain slope: ±0.02 dB/MHz maximum
• RF level adjust range: 0 to 20 dB via PIN diode attenuator
Stability & Linearity
• Gain stability (constant drive, constant temperature): ±0.25 dB/24 hours maximum after 30-minute warmup
• Gain stability over operating temperature range: ±1.0 dB maximum
• Gain variation across 40 MHz band: 0.5 dB peak-to-peak maximum
• Gain variation across 800 MHz band: 2.5 dB peak-to-peak maximum
• AM/PM conversion: 2.5°/dB maximum at 8 dB below rated power (1.0°/dB with optional linearizer)
Impedance & Harmonic Performance
• Input VSWR: 1.25:1 maximum
• Output VSWR: 1.25:1 maximum
• Load VSWR (continuous operation): 2.0:1
• Harmonic output: -60 dBc (second and third harmonics at rated power)
Spectral Purity
• Residual AM: -50 dBc below 10 kHz; -85 dBc above 500 kHz
• Phase noise: Meets IESS-308/309 profile at -6 dB relative to specification
• AC fundamental spurs: -36 dBc
• Sum of spurs (370 Hz to 1 MHz): -47 dBc
– Key Features
• Compact, lightweight construction optimized for space-constrained installations
• High efficiency operation minimizes prime power requirements
• ±0.25 dB/24-hour gain stability enables precision satellite uplink control
• Optional integral linearizer for improved AM/PM performance
• Designed and manufactured by Communications & Power Industries (CPI), formerly Varian Electron Device Group
– Typical Applications
• Satellite earth station uplink services
• Fixed satellite terminals
• Fly-away satellite communication systems
• Digital satellite news gathering (DSNG) vehicles
• Radar and communications systems
– Compatibility & Integration
The VZC-6962-D6A3 operates within standard C-band satellite allocations. Load VSWR capability to 2.0:1 continuous operation provides integration flexibility. Optional PIN diode attenuator enables 0 to 20 dB output level adjustment for system margin optimization.
