Development of measurement techniques in the microwave

It is increasingly common to integrate entire microwave systems (transmitter and receiver) on a single circuit board or semiconductor chip. Existing microwave measurement technology, however, requires that the systems have to be dismantled in order to measure and adjust the subsystems in a reliable manner - a procedure which is incompatible with volume manufacture.

Method

This project solves the above measurement problems by placing a probe over the circuit board containing the subsystems to be measured. This provides a noncontacting measurement system which does not require intervention in the measurement object, and does not disrupt its function significantly.

Through error correction of the signals picked up by the probe, the electrical properties reflection coefficient and power in the subsystems can be calculated. The probes are used with a power meter, spectrum analyser and scalar or vector network analysers which are common instruments in most microwave laboratories.

Aims

SP has competence today in the basic technology, see [1,2]. The project is now focussed on extending the technology to substrates with higher dielectric constant and to scale the technology down to allow measurements on smaller structures such as on alumina substrates and later microwave monolithic integrated circuits (MMIC). These building techniques give smaller circuits and thus require a miniaturisation of the noncontacting measurement technique.

References

[1] K. Yhland and J. Stenarson,  "Noncontacting Measurement of Power in Microstrip Circuits," presented at ARFTG, San Francisco, 2006.
[2] K. Yhland and J. Stenarson, ,  "Noncontacting measurement of reflection coefficient and power in planar circuits up to 40 GHz," presented at 69th ARFTG Conference, Honolulu Hawaii, 2007.