Mixers with improved linearity
AssigneeAnalog Devices, Inc.
InventorByungmoo Min
Life of this patent
Estimating the term…
Abstract
Systems and methods are disclosed for improved linearity performance of a mixer. An example mixer includes switching circuit elements configured to be switched on and switched off based at least partly on a local oscillator signal and capacitors including a respective capacitor in parallel with each of the switching elements. The mixer is configured to mix the input signal with the local oscillator signal to thereby frequency shift the input signal.
Claims20
A mixer for mixing an input signal with a local oscillator signal, the mixer comprising:
- switching circuit elements configured to be switched on and switched off based at least partly on the local oscillator signal, wherein the switching circuit elements are field effect transistors;
- and
- capacitors comprising a respective capacitor connected between a source and a drain of each of the field effect transistors, wherein the capacitors provide leakage current in the current path during a zero crossing transition time of the local oscillator signal to cause linearity of the mixer to be improved;
- wherein the mixer is configured to mix the input signal with the local oscillator signal to thereby frequency shift the input signal.
A mixer for mixing an input signal with a local oscillator signal, the mixer comprising:
- at least four diodes configured to switch based at least partly on the local oscillator signal, the at least four diodes being arranged in a ring;
- and
- capacitors, each of which is arranged in parallel with a respective diode of the at least four diodes arranged in the ring;
- wherein the mixer is configured to mix the input signal with the local oscillator signal to thereby frequency shift the input signal,
- wherein the at least four diodes and the capacitors are arranged such that leakage current flows across the at least four diodes during a zero crossing transition time of the local oscillator signal, and wherein substantially no leakage current flows across the at least four diodes during a different time.
A method for mixing an input signal with a local oscillator (LO) signal with improved linearity, the method comprising:
- receiving, at inputs of a mixer, the input signal and the LO signal;
- and
- mixing, with switching elements of the mixer, the input signal and the LO signal to generate a frequency shifted input signal, wherein the switching elements and a plurality of capacitors are arranged such that leakage current flows across the switching elements during a zero crossing transition time of the LO signal to improve linearity of the mixer,
- wherein each capacitor of the plurality of capacitors is in parallel with a current path of a respective switching element of the switching elements.
Dependencies are inferred from the claim text.