A new Spacecraft Transponding Modem (STM) is being developed for deep space communication applications. The STM receives an X-band (7.17 GHz) uplink signal and generates an X-band (8.4 GHz) and a Ka-band (32.0 GHz) coherent or noncoherent downlink signals. The STM architecture incorporates two miniature linear phase modulators. These modulators are used to modulate the X-band and Ka-band downlink frequencies with the downlink telemetry, turnaround ranging, or regenerative PN-ranging signals. The linear phase modulators are designed with custom developed MMIC chips. The phase modulator MMICs, the amplifiers, and driver circuits are laid out on drop-in alumina substrates. These modulator designs meet the following requirements: phase deviation range of /spl plusmn/140 degrees at X-band and Ka-band downlink carrier frequencies, phase linearity of less than 8%, phase modulation input bandwidth of greater than 100 MHz, and differential input with sinewave or squarewave modulating format.
Development of linear phase modulator for spacecraft transponding modem
2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542) ; 3 ; 3/1233-3/1241 vol.3
2001-01-01
962627 byte
Conference paper
Electronic Resource
English
The NASA Spacecraft Transponding Modem
British Library Conference Proceedings | 2000
|The NASA Spacecraft Transponding Modem
NTRS | 2000
|