Inverter

Abstract

A frequency converter includes a multiphase local oscillator and a multiphase mixer. The mixer includes a plurality of mixer switches, each mixer switch being connected to a corresponding amplifier. A local oscillator is configured to provide switching signals to each mixer switch, and includes a plurality of inverters, configured as a ring oscillator.

Description

technical field [0001] The invention relates to a frequency converter comprising a local oscillator and a mixer, for use eg in a radio receiver. Background technique [0002] There is a need for low cost radio receivers with good performance. A low power architecture, and the ability to produce the receiver monolithically is preferred, eg using a MOS (Metal Oxide Semiconductor) process. In the prior art, such as described in patent document EP2408118, an LC (inductance-capacitance) resonant tank is used to provide a local oscillator signal which is used by a mixer to convert the desired channel from the received radio frequency ( RF) to intermediate frequency (IF). [0003] LC resonant tanks are used in prior art because of their relatively low phase noise. However, producing an LC resonant tank with the necessary tuning range and performance can be expensive, for example because it typically requires a relatively large silicon area. One way to achieve a wide regulation ...

AI Technical Summary

Problems solved by technology

[0004] Ring oscillators are another way to provide a local oscillator signal, but existing ring oscillators are typically not suitable for use in frequency converters due to their relatively high phase noise

Further, existing ring oscillators may not be suitable for use in mixers because they provide overlapping outputs, or have unsuitable duty cycles

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