Quasi-optical antenna-mixer array composed of a magnetic loop antenna operated at 10-GHz band

The quasi‐optical antenna‐mixer is a receiving system that spatially receives RF signals and local oscillator (LO) signals and at the same time converts the RF signals to intermediate (IF) frequency signals. The line transmission loss, which causes a problem at millimeter wave frequencies, can be suppressed. In this paper, test fabrication and measurement of a quasi‐optical antenna‐mixer array receiving RF and LO signals with a magnetic loop antenna are carried out at 10 GHz and quasi‐optical mixing is shown to be possible. A two‐dimensional array antenna using this element is proposed. Its receiving characteristics are theoretically predicted. By changing the illumination angle or frequency of the LO, it is found that the receiving direction of the RF can be scanned. In addition, the suppression of RF and LO signals appearing at the output end is demonstrated. An experiment with a two‐dimensional array consisting of eight elements of quasi‐optical antenna‐mixers is carried out and the validity of the proposal is confirmed. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(4): 45–53, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10114