Hyuk-Ja Kwon

94 GHz CPW branch-line bandpass filter for planar integrated millimeter-wave circuits

We report the 94 GHz CPW branch-line bandpass filter for planar integrated millimeter- wave circuits. The basic idea is to use the branch-line coupler as a transversal filtering section by connecting the coupled ports to the open load stubs and taking the isolated port as the output node. The 94 GHz bandpass filter exhibits an insertion loss of 2.5 dB with an 11.7 % 3 dB relative bandwidth at a center frequency of 94 GHz and the return loss is better than -18 dB at a center frequency. The designed and fabricated 94 GHz bandpass filter shows the good performance for planar integrated millimeter-wave circuits.

A 94 GHz diode mixer for low LO power operation

For low LO power and broadband characteristics of the mixer, an antipodal fin-line to microstrip transition for operation in the 94 GHz frequency has been designed and characterized. Back to back transitions fabricated on soft substrates have been measured and simulated to verify their behavior. A single balanced fin-line mixer was designed and fabricated. In the mixer, a wideband fin-line to coplanar waveguide 180/spl deg/ balun and low pass filter were used. Conversion loss is less than 10 dB at LO power of 6 dBm.

Implementation and Performance Analysis of the Single Channel Monopulse System

In this paper, we have studied the tracking system with a single channel monopulse receiver that has a comparative advantage of costs, size, weight, and power consumption over the general 3-channel monopulse receivers. After the single channel monopulse system was composed of an antenna, a monopulse receiver, a servo unit, a RF signal processor unit and a power supply unit, we analyzed the basic tracking performance of the tracking error angle and the pointing loss. And we proved the tracking performance to a moving target in the outdoor environment. On the Analysis of the tracking test results, the single channel monopulse system shows a equal or higher performance over the general 3-channel monopulse system and also has advantages of the system implementation. Also, it is concluded that this study is useful to apply a single channel monopulse receiver with benefits of production price and miniaturization when the monopulse tracking systems will be developed in the future.