Various methods and circuital arrangements for reducing a turn ON time of a cascode amplifier are presented. According to one aspect, a configurable switching arrangement coupled to a cascode transistor of the amplifier shorts a gate of the cascode transistor to a reference ground during an inactive mode of operation of the amplifier. During an active mode of operation of the amplifier, the configurable switching arrangement couples a gate capacitor to the gate of the cascode transistor that is pre-charged to a voltage that is higher than a gate biasing voltage to the cascode transistor, which ensures that cascode transistor turns ON much quicker than the traditional method of grounding the cap, hence provide a final current flow through the cascode amplifier in a shorter time by not limiting the turn ON time of the input transistor. The gate biasing voltage is coupled to the gate capacitor via a resistor. A relationship between the pre-charged voltage, and minimum saturation voltages and threshold voltages of the transistors of the cascode amplifier is also provided.

Various methods and circuital arrangements for reducing a turn ON time of a cascode amplifier are presented. According to one aspect, a configurable switching arrangement coupled to a cascode transistor of the amplifier shorts a gate of the cascode transistor to a reference ground during an inactive mode of operation of the amplifier. During an active mode of operation of the amplifier, the configurable switching arrangement couples a gate capacitor to the gate of the cascode transistor that is pre-charged to a voltage that is higher than a gate biasing voltage to the cascode transistor, which ensures that cascode transistor turns ON much quicker than the traditional method of grounding the cap, hence provide a final current flow through the cascode amplifier in a shorter time by not limiting the turn ON time of the input transistor. The gate biasing voltage is coupled to the gate capacitor via a resistor. A relationship between the pre-charged voltage, and minimum saturation voltages and threshold voltages of the transistors of the cascode amplifier is also provided.

Various methods and circuital arrangements for biasing gates of stacked transistors of a cascode amplifier are presented, where the amplifier is configured to operate according to different modes of operation. Such circuital arrangements operate in a closed loop with a feedback voltage that is based on a sensed voltage at one or more nodes of a replica circuit of the stacked transistors, the amplifier and the replica circuit biased with same gate voltages. According to one aspect, one gate voltage is adjusted based on a comparison of the feedback voltage with a reference voltage, and other gate voltages are derived by offsetting of the one gate voltage with voltages generated by a current flow through a resistive ladder network.

Various methods and circuital arrangements for biasing gates of stacked transistors of a cascode amplifier are presented, where the amplifier is configured to operate according to different modes of operation. Such circuital arrangements operate in a closed loop with a feedback voltage that is based on a sensed voltage at one or more nodes of a replica circuit of the stacked transistors, the amplifier and the replica circuit biased with same gate voltages. According to one aspect, one gate voltage is adjusted based on a comparison of the feedback voltage with a reference voltage, and other gate voltages are derived by offsetting of the one gate voltage with voltages generated by a current flow through a resistive ladder network.

A system for split-frequency amplification, preferably including: one or more primary-band amplification stages, one or more secondary-band amplification stages, one or more band-splitting filters, and/or one or more signal couplers. An analog canceller including one or more split-frequency amplifiers. A mixer including one or more split-frequency amplifiers. A voltage-controlled oscillator including one or more split-frequency amplifiers. A method for split-frequency amplification, preferably including: receiving an input signal, separating the input signal into signal portions, and/or amplifying the signal portions, and optionally including combining the amplified signal portions and/or providing one or more output signals.

Various methods and circuital arrangements for protection of an RF amplifier are presented. According to one aspect, the RF amplifier is part of switchable RF paths that may include at least one path with one or more attenuators or switches that can be used during normal operation to define different modes of operation of the at least one path. An RF level detector monitors a level of an RF signal during operation of any one of the switchable RF paths and may control the attenuators or switches to provide an attenuation of the RF signal according to a desired level of protection at an input and/or output of the RF amplifier. According to another aspect, the RF level detector may control a switch to force the RF signal through a different switchable RF path.

Various methods and circuital arrangements for protection of an RF amplifier are presented. According to one aspect, the RF amplifier is part of switchable RF paths that may include at least one path with one or more attenuators or switches that can be used during normal operation to define different modes of operation of the at least one path. An RF level detector monitors a level of an RF signal during operation of any one of the switchable RF paths and may control the attenuators or switches to provide an attenuation of the RF signal according to a desired level of protection at an input and/or output of the RF amplifier. According to another aspect, the RF level detector may control a switch to force the RF signal through a different switchable RF path.

Provided is an amplification circuit for amplifying an input signal. The amplification circuit includes an input stage including an input matching circuit that receives the input signal and an input attenuation circuit that attenuates a gain for the input signal outside an operating frequency band of the amplification circuit, a transistor that amplifies the input signal provided from the input stage, and an output stage including an output matching circuit that receives a signal amplified by the transistor and an output attenuation circuit that attenuates the gain for the input signal outside the operating frequency band of the amplification circuit, and the input attenuation circuit includes a first resistor and a second resistor that are connected to a ground voltage, a first passive element connected between the input matching circuit and the second resistor, and a second passive element connected between the first passive element and the first resistor.

Apparatus for performing offset cancellation is disclosed. The apparatus comprises a gating circuit (6) for receiving an analogue signal (3) from a source (2) and providing a gated analogue signal (9) to an analogue circuit (10), a gating controller (7; 14; FIG. 1) and a digital processor (14; FIG. 1) for receiving a digital signal (13) converted from an analogue output (11) from the analogue circuit (10). The gating circuit comprises at least one path (21.sub.1), each path respectively comprising, an input terminal (22.sub.1), an output terminal (23.sub.1), a node (24.sub.1) interposed between the input and output terminals, a first transistor (Q1) having a channel arranged between the input terminal and the node, and a second transistor (Q3) having channel arranged between the node and a fixed reference, such as ground (GND). The gating controller is configured, in a first time window (15.sub.A), to switch the first transistor so that the input terminal and the output terminal are decoupled and to switch the second transistor so that the node is coupled to the fixed reference. The gating controller is configured, in a second, different time window (15.sub.B), to switch the second transistor so that the node and the fixed reference are decoupled and to switch the first transistor so that the input terminal is coupled to the input terminal. The digital processor is configured, in the first time window, to take a first measurement of the digital signal, and, in the second, different time window, to take a second measurement of the digital signal. The digital processor configured to subtract the first measurement from the second measurement.

A low noise amplifier that includes a first cascode, a second cascode, an input circuit, an output node, a first switch, and a second switch. A source of a first common gate transistor and a drain of a first common source transistor of the first cascode are coupled to a first node of the low noise amplifier. The output node is coupled to a drain of the first common gate transistor, and to a drain of a second common gate transistor of the second cascode, thereby coupling the first cascode and the second cascode to a power supply via a load. The first switch is coupled between a gate of the first common gate transistor and the power supply. The second switch is coupled between the first node and the power supply. The first switch is configured to be open and the second switch is configured to be closed when the low noise amplifier operates at a first operational node. The first switch is configured to be closed and the second switch is configured to be open when the low noise amplifier operates at a second operational node that differs from the first operational mode by at least a gain of the low noise amplifier.