Submillimeter-wave phasor beam-pattern measurement based on two-stage heterodyne mixing with unitary harmonic difference
Journal
IEEE Transactions on Microwave Theory and Techniques
Journal Volume
55
Journal Issue
6
Pages
1200-1207
Date Issued
2007-06
Author(s)
Subjects
A near-field phasor beam measurement system is developed for the characterization of heterodyne receiver optics at submillimeter-wave frequencies. The system synthesizes a pair of submillimeter-wave signals as the RF and local oscillator (LO) sources from common reference sources. The synthesized harmonic numbers of the RF and LO sources are arranged with difference by one, which makes this a new configuration with a unitary harmonic difference. The coherent RF and LO signal are down-converted by the receiver under test, then mixed with the microwave-frequency common reference signal to generate the second-order IF signal around 100 MHz for amplitude and phase comparison. The amplitude and phase fluctuation of the measurement system at 683 GHz is within ±0.2 dB and ±4° in a 1-h period, respectively. The system dynamic range at 683 and 250 GHz can be as high as 43 and 47 dB, respectively. The system is then used to measure the receiver beam patterns at 683 and 250 GHz with different RF transmitting probe antennas. © 2007 IEEE.
Other Subjects
Frequency conversion; Gaussian beams; Phase measurement; Submillimeter-wave receivers
Type
journal article