A subharmonic mixer using a planar doped barrier diode with symmetric conductance

Planar doped barrier (PDB) diodes with symmetric IV characteristics have been successfully used in a subharmonically-pumped coplanar stripline mixer circuit. A conversion loss around 6 dB has been measured using a 1.2 GHz local oscillator at a pump power of 7 dBm and a 2 GHz signal frequency for large area, 100 µm diameter PDB mesa diodes. The particular advantages of this device structure are that a single PDB replaces two critically matched Schottky barrier diodes in conventionally balanced mixers, and the PDB's designable barrier height reduces the local oscillator power requirement.