Linvill Stability Circle



Flair for innovative design (UK and USA patents)

Analytical strength

In-depth understanding of underlying principles

A winning and communicative style of management

Determination to succeed and meet project time scales

Methodical manner of working

Bob’s Radio Know-how has innovated a PHY and MAC (Layer-1) technology (Thalassik) for
telemedical and telecare applications in the CEPT Short-Range Device (SRD) band. 
A paper presented to the DTI’s WiSIG KTN can be read, please click here.

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.



Framing structure

CEPT SRD allocations

Computer-aided selection of first i.f. avoid all EMC infractions using TxRx_planner and published radio allocations.