A UHF telemetry converter employing integrated microwave circuits

A solid-state telemetry converter is described which converts the 2.2 - 2.3 GHz telemetry band to the 215 - 315 MHz telemetry band. A microwave interdigital multiplexing filter acts as a preselector, a local oscillator filter and an intermediate frequency filter. The filter structure contains integrated semi-conductor elements which perform the necessary frequency conversions. The output of a crystal controlled oscillator is multiplied by a step recovery diode to the appropriate local oscillator frequency and mixed in a hot carrier diode mixer. An IF preamplifier provides an efficient 20 db RF to IF gain. Some of the advantages of the "Integrated" approach over the "Modular" approach are discussed.