Stellant Systems announced that they have completed the shipment of spaceflight-qualified 35-W Q-band linearized channelized traveling-wave tube amplifiers (LCTWTAs) that operate from 40 - 42 GHz in a conduction-cooled package. Thirty-one (31) integrated LCTWTAs were delivered for a high-throughput satellite (HTS) application that will be able to deliver Gbps-level total data transfers via downlink.
The model 2000HDA-A16 LCTWTA consists of a linearized channel amplifier (LCAMP), traveling-wave tube (TWT), and an electronic power conditioner (EPC). This LCTWTA produces a minimum of 35 W RF power at end-of-life (EOL) across the frequency band. The TWT itself is qualified for operation up to 200 W over the full 37.5 to 42.5 GHz Q-band allocation representing the highest CW power helix TWT qualified for space applications at Q-band. These LCTWTAs enable gigabit-per-second (Gbps) data rates by providing unprecedented power, efficiency, and linearity for a Q-band downlink.
Fig. 1 Electronic Power Conditioner
Traveling-Wave Tube (TWT)
The TWT model 9922HA employs a helical RF circuit with periodic, permanent magnet (PPM) focusing packaged for conduction cooling. The electron gun is a dual-anode, isolated-focus-electrode design, and is designed for greater than 15 years of mission life. The helix circuit is designed to provide CW saturated RF output at 35 W RF over the 40 to 42 GHz Q-band frequency range.
Electronic Power Conditioner (EPC)
The electronic power conditioner (EPC) shown in Fig. 1 is the 7-kV model 2000HDA is capable of processing over 300 W of DC power. The EPC can be configured to accept either regulated or unregulated spacecraft bus voltages of up to 100 volts. The EPC efficiency ranges between 91% and 95% depending on the spacecraft bus voltage interface and the extremes of the environmental requirements.
LCTWTA Performance
The Stellant LCAMP is shown in the middle of Fig. 1. An LCAMP consists of a channel amplifier (CAMP) and linearizer. The LCTWTA has an input dynamic range from -49 dBm to -13 dBm with 36 gain steps in 1.0 ± 0.3 dB increments in Fixed Gain Mode (FGM). In ALC mode, this LCTWTA has a minimum control range of +2 to -13 dB relative to saturation with 36 gain steps in 0.5 dB ± 0.25 dB increments, and linearizer provides ~5 dB gain expansion and 40° phase expansion over swept power with 20° intentional phase expansion variation across frequency to match TWTA characteristics.
These linearized channelized traveling-wave tube amplifiers (LCTWTAs) provided by Stellant Systems with help achieve Gbps-level downlink in the satellite applications.
