Communication modules

Radiation-Hardened, High-Data-Rate Ka-Band Modulator and Transmitter

Technology Details
NASA requires that all future “near-Earth” missions (near-Earth defined as any spacecraft within one million kilometers of Earth) requiring more than 10 MHz of downlink data bandwidth operate in the 25.5 to 27.0 GHz band. Developed for NASA’s Solar Dynamics Observatory mission and adapted for the Lunar Reconnaissance Orbiter mission, this spaceflight
transmitter meets and/or exceeds all of NASA’s performance requirements and is the first to be designed for Ka-band.
How it works
This design consists of a phase-locked oscillator; a high-bandwidth, QPSK vector modulator; a medium-power, Ka-band solid-state power amplifier, a highly efficient DC-DC converter; and radiation-hardened, high-rate driver circuitry that receives I and Q channel data. The radiation-hardened design enables the Ka-band communications downlink system to transmit
130 Mbps of data (300 Msps after data encoding) to the ground system. The low error vector magnitude of the modulator reduces the implementation loss of the transmitter in which it is used, thereby increasing the overall communication system link margin.
Why it is better
Prior high-rate transmitters exist for X-band (~8 GHz) and Ku-band (~15 GHz), but those can’t take advantage of the Ka-band frequencies. This new Ka-band transmitter and modulator offer several unique design features that improve upon the current state of the art and enable the use of this high-frequency radio band. One design element that sets this technology apart is its unique packaging scheme and mechanical design that creates a compact, back-to-back cavity enclosure that utilizes die attach, substrate attach, wire bonding, and conventional surface mount technologies.

One Response to “Comms”

1. Rolando Rudnitski says:

   February 15, 2010 at 12:49 AM

   I never would have imagined that I needed to know all this. I DID need to know this! Thank goodness for Yahoo.