Biasing of radio frequency switches for fast switching
AssigneeAnalog Devices Global Unlimited Company
InventorsTurusan Kolcuoglu, Huseyin Kayahan, Yusuf Alperen Atesal
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Abstract
Apparatus and methods for biasing radio frequency (RF) switches to achieve fast switching are disclosed herein. In certain configurations, a switch bias circuit generates a switch control voltage for turning on or off a switch that handles RF signals. The switch bias circuit provides the switch control voltage to a control input of the switch by way of a resistor. Additionally, the switch bias circuit pulses the switch control voltage when turning on or off the switch to thereby shorten switching time. Thus, the switch can be turned on or off quickly, which allows the switch to be available for use soon after the state of the switch has been changed.
Claims21
A radio frequency (RF) system with fast switching speed, the RF system comprising:
- an RF switch including a control input that controls an impedance of the RF switch;
- a switch bias circuit configured to receive a control signal for selectively controlling a state of the RF switch, the switch bias circuit including:
- a delay circuit configured to time a delay duration in response to a transition of the control signal;
- and
- a logic circuit configured to select a switch control voltage based on the control signal and configured to change the selection of the switch control voltage after the delay duration;
- and
- a resistor electrically connected between an output of the switch bias circuit and the control input to the RF switch,
- wherein the switch bias circuit is configured to pulse the switch control voltage in response to the transition of the control signal to thereby shorten a delay in switching the RF switch.
(canceled)
A method of switch control to provide fast switching speed, the method comprising:
- controlling an impedance of a radio frequency (RF) switch using a switch control voltage from a switch bias circuit, including providing the switch control voltage from an output of the switch bias circuit to a control input of the RF switch through a resistor;
- providing a control signal to a control logic circuit and to a delay circuit that is configured to time a delay duration, the control signal indicating whether to turn on or turn off the RF switch;
- generating a pulse of the switch control voltage for a delay duration in response to a transition of the control signal to thereby shorten a delay in switching the RF switch;
- and
- changing the switch control voltage after the delay duration while the control signal is provided to the logic control circuit.
A radio frequency (RF) switching circuit comprising:
- a field-effect transistor (FET) switch including a gate;
- a switch bias circuit configured to receive a control signal and to output a switch control voltage;
- and
- a resistor configured to provide the switch control voltage to the gate of the FET switch,
- wherein the switch bias circuit is configured to generate a turn-on pulse of the switch control voltage in response to a transition of the control signal from an off state to an on state and to generate a turn-off pulse of the switch control voltage in response to a transition of the control signal from the on state to the off state, the switch bias circuit comprising:
- a delay circuit configured to time a delay duration when the control signal transitions;
- and
- a logic circuit configured to change the switch control voltage in response to a change in the control signal and configured to change the switch control voltage after the delay duration after the change in the control signal.
Dependencies are inferred from the claim text.