A fully integrated radar receiver front end including an active tunable band pass filter and an image rejection mixer

A fully integrated X-band radar receiver front end based on only one down converting stage has been designed. The two chip MMIC (monolithic microwave integrated circuit) front end includes an active tunable bandpass filter in combination with an image rejection mixer. A novel digital time shifter is utilised to accomplish the tunability of the bandpass filter. The tuning range of the filter is between 8.7 and 9.8 GHz. With the intermediate frequency (IF) equal to 360 MHz, the total image rejection of the front end exceeds 45 dB. These results indicates that a compact one chip X-band radar receiver front end can be achieved.