Analog Devices Global

Bilal Tarik Cavus

Yusuf Atesal

Turusan Kolcuoglu

Ozgun Serttek

Celal Avci

Mehmet Bati

A wide range differential current switching circuit can operate across a wide range of input currents and across a broad range of frequencies. A first differential current source can include a first transistor and a second transistor. The first transistor receives a switching signal and provides an output current and at output node. The second transistor receives an inverted switching signal, the first transistor and the second transistor coupled to each other at a tail node. A current source provides an input current to the tail node. A third transistor can provide a boost current to the tail node while the first transistor is off.

Current switching circuit

An inverter based on a compound semiconductor uses a depletion mode transistor as the pull-up device, and a current source to bias the pull-up device. The current source is electrically coupled to a source terminal of the pull-up device. As a result, the current source continues to conduct current through the pull-up device, whether the inverter output is high or low, to ensure rapid response of the inverter.

Compound semiconductor based inverter

Apparatus and methods for biasing radio frequency (RF) switches are provided herein. In certain configurations, an RF switching circuit includes a field effect transistor (FET) switch electrically connected between a first terminal and a second terminal, and an adaptive biasing circuit that generates a bias voltage used in part to bias a gate of the FET switch. The adaptive biasing circuit includes a low pass filter that generates a low pass filtered voltage based on low pass filtering a voltage of the first terminal, a buffer circuit that receives the low pass filtered voltage and generates a buffered voltage, and a voltage shifting circuit that generates the bias voltage by shifting the buffered voltage by an amount of voltage that depends on a state of a switch control signal.

Apparatus and methods for biasing radio frequency switches

A control circuit is provided for controlling the voltage at the gate terminal of a field effect transistor acting as a switch. The voltage, at for example, the source terminal of the transistor can be provided to a low pass filter and is then voltage translated to provide the gate signal. The filtering can be arranged so as to compensate for the effect of parasitic capacitances within the transistor, thereby linearizing its frequency response. The voltage translation can help to limit voltage differences between the gate and channel of the transistor. This can be significant as relatively fast transistors, as might be used in microwave circuits, may fail with relatively modest voltages at their gates.

Method of and apparatus for biasing switches

Apparatus and methods for radio frequency (RF) switches are provided herein. In certain implementations, an RF switching circuit includes an adaptive switch bias circuit that controls gate and/or channel voltages of one or more field effect transistor (FET) switches. Additionally, the adaptive switch bias circuit is powered by a power high supply voltage and a power low supply voltage, and can be used to selectively turn on or off the FET switches based on a state of one or more switch enable signals. The adaptive switch bias circuit adaptively biases that gate and/or channel voltages of the FET switches based on a voltage difference between the power high and power low supply voltages to provide switch biasing suitable for use with two or more different power supply voltage levels.

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Istanbul, Turkey

Bilal Tarik Cavus