p-i-n diode modulators for the K and Q frequency bands

An experimental investigation into extending the operation of p-i-n diode modulators from 18 Gc/s to 40 Gc/s is described. Wafers of stacked p-i-n diodes are considered but most success is achieved with arrays of unencapsulated post-mounted diodes. By reducing the dimensions of diodes of this type used at lower frequencies, broad-band modulators can be designed to operate at frequencies up to 40 Gc/s. A minimum on/off ratio of about 10 dB and an insertion loss of < 2 dB can be obtained over a 1.5 to 1 band of frequencies.