Polyphase phase shifter
AssigneeTexas Instruments Incorporated
InventorSudipto Chakraborty
Life of this patent
Estimating the term…
Abstract
In described examples, a quadrature phase shifter includes digitally programmable phase shifter networks for generating leading and lagging output signals in quadrature. The phase shifter networks include passive components for reactively inducing phase shifts, which need not consume active power. Output currents from the transistors coupled to the phase shifter networks are substantially in quadrature and can be made further accurate by adjusted by a weight function implemented using current steering elements. Example low-loss quadrature phase shifters described herein can be functionally integrated to provide low-power, low-noise up/down mixers, vector modulators and transceiver front-ends for millimeter wavelength (mmwave) communication systems.
Claims20
A circuit comprising:
- an input transistor configured to receive an input signal at a first frequency;
- a first phase generator that includes:
- a first phasing transistor coupled to the input transistor;
- a first modulator configured to receive a modulation signal at a second frequency that is different than the first frequency;
- and
- a first differential output coupled to the first modulator;
- a second phase generator that includes:
- a second phasing transistor coupled to the input transistor;
- a second modulator configured to receive the modulation signal;
- and
- a second differential output coupled to the second modulator;
- a first transformer inductively coupled between the first modulator and the first phasing transistor;
- and
- a second transformer inductively coupled between the second modulator and the second phasing transistor.
A circuit comprising:
- an input transistor that includes a base configured to receive an input signal;
- an in-phase phase generator that includes:
- a first biasing network;
- an in-phase phasing transistor coupled to the input transistor that includes a base coupled to the first biasing network;
- an in-phase modulator configured to receive a modulation signal;
- an in-phase differential output coupled to the in-phase modulator;
- and
- a quadrature phase generator that includes:
- a second biasing network;
- a quadrature phasing transistor coupled to the input transistor that includes a base coupled to the second biasing network;
- a quadrature modulator configured to receive the modulation signal;
- a quadrature differential output coupled to the quadrature modulator;
- and
- a first transformer inductively coupled between the in-phase modulator and the in-phase phasing transistor;
- and
- a second transformer inductively coupled between the quadrature modulator and the quadrature phasing transistor.
Dependencies are inferred from the claim text.