Performance of Symmetrical MAC
Applying demanding analysis to the applied research of McDonald et al. at Canberra, I developed a numerical modelling tool for improving the common-base transistor(BJT ) configuration for a more robust low-noise amplifier (LNA). The Canberra findings, based on original work by Van der Ziel, have effectively revolutionised the theory of transistor noise, supplanting traditional BJT noise models, (e.g. Meyers-Gray).
The Linvill stability for the common-base circuit configuration can be modelled using my Excel scripts.
See PC generated plot of Linvill stability circle above.
I invented, designed, coded ( in C ) and documented “TxRx_planner” – a PC utility for aiding the design of front-end architectures of superhet radios for maximising EMC on the ‘air waves’. Granted UK patent 2372174, it has been filed also in the USA. Gaining corporate sponsorship, I went on to present it as an I.E.E. paper and software demonstration at The 9th International Conference on HF Radio Systems and Techniques, 23-26th June, Bath.
EMC infringements by blind adoption of 70MHz first i.f. include spurious responses to neighbouring radio broadcasts, and unintended interference to sensitive third-party receivers.
Seriousness of threats to EMC as function of first i.f. Joint deep minimum indicates best range of choices.
CEPT SRD allocations
Computer-aided selection of first i.f. avoid all EMC infractions using TxRx_planner and published radio allocations.