Energy-efficient oscillator

Inventor: Massoud Tohidian

2015 09 Patent oscillator DEF.jpg

Cheaper and better. With such succinct words of praise, a product is sure to sell itself. However, the practical application wasn’t the central concern when Dr Massoud Tohidian was designing his extremely small, accurate and energy-efficient oscillator. In his own words: ‘Our primary focus was on developing a new type of circuit’. In September, the native Iranian obtained his doctorate from the Electronics (ELCA) research group of the Microelectronics Department, part of the Faculty of Electrical Engineering, Mathematics and Computer Science. Earlier this year, he and three colleagues (among whom PhD-student Amir-Reza Ahmadi-Mehr) founded Qualinx, the company that holds patents including that for Tohidian’s oscillator. For although his initial motivation was perhaps academic, he now believes that he’s developed a ready-to-market product. Oscillators can be found in nearly all electronic devices. They generate the frequencies upon which mobile telephones, for example, communicate with each other. Up until now, manufacturers had a choice of two types, each with their own pros and cons. The ring oscillator is small (e.g. 0.01 m2 chip area) and cheap. However, these oscillators generate a high amount of phase noise, which makes them inaccurate.

Minimizing this noise uses up lots of energy, which means a battery runs down quickly. The second type is the LC oscillator. This type is low phase noise, but also larger (e.g. 0.2 m2) and so more expensive. Tohidian’s oscillator comes in two versions: one that’s extremely small with low phase noise and low energy usage, and another that’s the same size as an LC oscillator, but a lot more accurate. Practical considerations were behind Tohidian’s decision not to sell the patent. ‘Clients don’t place their trust in a single prototype. They want to see it in a larger system with their required characteristics’. Through Qualinx, he expects to be able to deliver precisely that.

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