mm-wave

The design of electronic equipment operating at mm-wave frequencies requires a change of methodology and increased attention to detail. Plextek has proven mm-wave design experience at frequencies from 28GHz to 94GHz. We can combine the necessary mm-wave know-how with a strong background in high volume product design. This allows us to develop cost-competitive mm-wave modules and sub-systems suitable for commercial exploitation. Our mm-wave design capabilities include mm-wave MMICs, Multi-Chip Modules (MCMs) and waveguide components. We can assist with the development of mm-wave equipment such as automotive radar at 24GHz and 77GHz, point to point links at 38GHz and 60GHz, cost-competitive radar components at 35GHz and radiometer receivers for passive mm-wave imaging. Examples of some of our mm-wave product designs are given below.

The traditional applications for mm-wave equipment were low volume military systems and radio astronomy. Components and systems were produced in low volume, were expensive, had long lead-times and were often hand-tuned on an individual basis. The end user accepted this and believed it an inevitability of the high operating frequency. Fortunately all of this has now changed and mm-wave equipment can now be developed for cost-competitive, volume manufacture.

One important development, that has helped enormously in the realisation of reproducible, low-cost, non-tuned mm-wave components, has been the capability to fabricate GaAs ICs at mm-wave frequencies. Plextek has extensive experience in designing GaAs ICs on foundries in Europe, the USA and Japan. Over the past six years we have designed over 30 GaAs Monolithic Microwave Integrated Circuits (MMICs), many of which have been mm-wave designs, such as the 42GHz power amplifier shown to the right.

Plextek is also able to develop multi-function modules such as transceivers or FMCW radar front-ends, comprising MMICs, discretes and printed circuitry. The photograph to the right shows a 27.5GHz - 29.5GHz upconverter, which has a measured gain of 43dB (adjustable over a 15dB range) and a 1dB compressed output power of +23dBm. No microwave chip capacitors are used, all de-coupling is realised with 0402 SMT components. The carrier substrate is 5880 Duroid with a thick metal backing to provide rigidity. This results in a highly reproducible and potentially low-cost design.

Many mm-wave modules require waveguide interfaces and Plextek has experience of designing waveguide housings and transitions. The photograph to the left shows a low-cost 28GHz waveguide rotary joint. This development resulted in a rotating waveguide to co-axial transition, requiring no tuning, with an insertion loss of ‹ 0.2dB. Other innovative mm-wave work in which Plextek has been involved includes the development of low cost, lightweight metallised plastic components such as the Q-band horn antenna shown at the top of the page. Also shown at the top of the page is a re-configurable 42GHz E-plane filter. The pass-band and rejection of the filter can be adjusted by simply replacing the low cost E-plane insert (septum) whilst retaining the same housing. A number of septums are shown, these were etched parts but in high volume, stamping could reduce the cost still further.

Please contact us if you would like to discuss your specific requirements for mm-wave design capabilities.