ALMA Memo 432		
26 August 2002

A Split-Block Waveguide Directional Coupler

A. R. Kerr and N. Horner
National Radio Astronomy Observatory
Charlottesville, VA 22903, USA


ABSTRACT

A simple waveguide directional coupler is described which uses the split-block type of construction common in millimeter-wave components.  The coupler uses an array of metal probes suspended on quartz stand-offs.  Depending on the number of coupling elements, the coupling can be in the range 15-30 dB, with typically ± 2 dB variation across the waveguide band, and directivity  > 10 dB.  The coupler, intended for injecting local oscillator power into a waveguide mixer, can be scaled for operation in any waveguide band.

Keywords: Directional couplers, Waveguide couplers, Millimeter wave directional couplers, Millimeter wave circuits.