Patent ID: 8411795
Filing Date: 2013-04-02
Classification: H01P

Abstract:
1. A digitally controlled phase shifter, comprising: an input receiving an RF input signal; a first 90 degree hybrid coupler receiving the RF input signal and splitting the signal into first and second signals having a 90 degree phase difference; a first delay path receiving the first signal and providing a first delayed signal, comprising a first single pole multi-throw Micro-Electro-Mechanical switch responsive to a first digital control signal, a second single pole multi-throw Micro-Electro-Mechanical switch responsive to a second digital control signal, and a first plurality of delay lines having differing delays coupled between said first and second single pole multi-throw Micro-Electro-Mechanical switches, wherein said first and second single pole multi-throw Micro-Electro-Mechanical switches select one of said first plurality of delay lines in response to said first and second control signals; a second delay path receiving the second signal and providing a second delayed signal, comprising a third single pole multi-throw Micro-Electro-Mechanical switch responsive to a third digital control signal, a fourth single pole multi-throw Micro-Electro-Mechanical switch responsive to a fourth digital control signal, and a second plurality of delay lines having differing delays coupled between said third and fourth single pole multi-throw Micro-Electro-Mechanical switches, wherein said third and fourth single pole multi-throw Micro-Electro-Mechanical switches select one of said second plurality of delay lines in response to said first and second control signals; a second 90 degree hybrid coupler receiving the first and second delayed signals and providing first and second delayed output signals having a 90 degree phase difference; a combiner receiving the first and second delayed output signals and combining them to provide a phase shifted output signal; an output receiving the phase shifted output signal; and a control circuit receiving one or more phase shift control signals and outputting said first, second, third and fourth digital control signals to said first, second, third and fourth single pole multi-throw Micro-Electro-Mechanical switches, wherein said control circuit comprises input control logic and a Micro-Electro-Mechanical switch driver circuit, wherein said input control logic is coupled to receive said phase control signals and provides digital inputs to said Micro-Electro-Mechanical switch driver circuit.