Glitch reduction in phase shifters
AssigneepSemi Corporation
InventorsRavindranath D. SHRIVASTAVA, Fleming LAM, Payman SHANJANI
Life of this patent
Estimating the term…
Abstract
Methods and devices to reduce glitches in phase shifters implementing high isolation switches are disclosed. Such glitches occur at the output of the phase shifters when transitioning from one phase shift to another. The disclosed method implements delays in various steps of the phase shifter transitions. Exemplary embodiments implementing single-pole multi-throw are provided and exemplary performance of the disclosed methods are also presented. The described methods are also applicable to multi-step attenuators.
Claims21
-17. (canceled)
A phase shifter comprising:
- a) a first terminal and a second terminal
- b) a plurality of selectively switchable phase shifting paths connected between the first terminal and the second terminal;
- c) a control circuit configured to control switching of the plurality of phase shifting paths such that:
- in a given transition from a first phase shifting path to a second phase shifting path, an intermediary phase shifting path between the first and second phase shifting paths is activated to couple the first terminal to the second terminal via the intermediary phase shifting path before activating the second phase shifting path,
- wherein
- i) the intermediary phase shifting path is activated by decoupling its ends from ground, and coupling its ends to the first and second terminals;
- ii) then, the first phase shifting path is deactivated by decoupling its ends from the first and second terminals and coupling its ends to ground.
An attenuator comprising:
- a first terminal and a second terminal;
- a plurality of selectively switchable attenuating paths;
- a control circuit configured to control switching of the plurality of attenuating paths such that:
- during a transition from a first attenuating path to a second attenuating path, an intermediary attenuating path is activated between the first and second attenuating paths by decoupling its ends from ground;
- coupling its ends to the first and second terminals;
- then, the first attenuating path is deactivated by decoupling its ends from the first and second terminals;
- and coupling its ends to ground.
A method of transitioning from a first phase shift to a second phase shift in a phase shifter, the method comprising:
- activating an intermediary phase shifting path by decoupling ends of the intermediary phase shifting path from ground;
- coupling the ends of the intermediary phase shifting path to a first terminal and a second terminal;
- deactivating the first phase shifting path by decoupling its ends from the first and second terminals and coupling its ends to ground;
- wherein the intermediary phase shifting path is selected between the first and second phase shifting paths in a recursive sequence to minimize signal cancellation and glitch amplitude.
Dependencies are inferred from the claim text.