Salient Features of the CSU Electronic-scan X-band radar (FrontX)

This paper will review the salient features of the electronic-scan X-band radar system under development at Colorado State University. This radar is being developed in collaboration with FIRST RF Corporation of Boulder CO. The objective of this radar system is to demonstrate the dual-polarization measurement capability and also study the limits of phased array antennas on polarization measurements.

The radar consists of an X-band active array antenna that can radiate a peak power of 70 W. The array antenna generates a fixed beam in one axis, and it can scan electronically in the other plane (azimuth or elevation). The array is mounted to a bearing which allows the antenna to be rotated mechanically about boresite by 90 degrees. This will allow the electronic scan axis to be moved from azimuth to elevation and vice versa. The antenna is also mounted on a mechanical scanner that permits motion in azimuth and elevation. This permits comparison of electronic and mechanical scanning in either axis, specifically to study the polarization response.

The IF transmit waveform is generated using a digital exciter-receiver module developed at CSU. This module also accepts the received IF signals and performs multi-channel pulse compression. The multi-channel receiver allows the use of frequency and time diversity to separate the short- and long-pulse waveforms that the radar generates and receives.

The high bandwidth of the active array's transmit/receive is coupled with the agile digital exciter-receiver to produce a radar with very flexible capabilities. These capabilities will be leveraged in order to study the behavior of the phased array antenna relative to the CSU-CHILL dual-wavelength (S- and X-band) radar. Once basic operation is established, we will conduct exhaustive side-by-side comparisons of the phased array system against the CHILL radar.