A Novel Broadband IQ Modulator / Demodulator MMIC
Birkbeck, J
Roke Manor Research Ltd

Best-in-class commercially available microwave IQ (de)modulator modules typically cover an instantaneous bandwidth of up to 2-octaves, for example 1GHz to 4GHz. This bandwidth is generally limited by the ability to maintain accurate 90° phasing in the local oscillator feed, due to practicalities of the means generated.

A broadband IQ modulator / demodulator MMIC will be presented, which uses a novel but conceptually simple closed loop approach to maintain performance over a broad bandwidth.

Whilst this first implementation of the technique targets a bandwidth of 1-6GHz, the underlying method is inherently broadband in nature, and could be applied to Silicon RFICs as well as GaAs MMICs. Integrated Circuit based IQ (de)modulators will allow lighter and more compact flight equipment with improved performance.