Abstract: Modified silicon-on-insulator (SOI) substrates having a trap rich layer, and methods for making such modifications. The modified regions eliminate or manage accumulated charge that would otherwise arise because of the interaction of the underlying trap rich layer and active layer devices undergoing transient changes of state, thereby eliminating or mitigating the effects of such accumulated charge on non-RF integrated circuitry fabricated on such substrates. Embodiments retain the beneficial characteristics of SOI substrates with a trap rich layer for RF circuitry requiring high linearity, such as RF switches, while avoiding the problems of a trap rich layer for circuitry that is sensitive to accumulated charge effects caused by the presence of the trap rich layer, such as non-RF analog circuitry and amplifiers (including power amplifiers and low noise amplifiers).

Abstract: An RF switch to controllably withstand an applied RF voltage VSW, or a method of fabricating such a switch, which includes a string of series-connected constituent FETs with a node of the string between each pair of adjacent FETs. The method includes controlling capacitances between different nodes of the string to effectively tune the string capacitively, which will reduce the variance in the RF switch voltage distributed across each constituent FET, thereby enhancing switch breakdown voltage. Capacitances are controlled, for example, by disposing capacitive features between nodes of the string, and/or by varying design parameters of different constituent FETs. For each node, a sum of products of each significant capacitor by a proportion of VSW appearing across it may be controlled to approximately zero.

Abstract: A non-linear converter comprising a non-linear voltage divider having a plurality of resistors representing a non-linear transfer function, an analog multiplexer having analog multiplexer inputs coupled to the non-linear voltage divider and configured to output an analog multiplexer output, the analog multiplexer chooses one of the plurality of resistors based on a logic signal and the non-linear transfer function, an analog comparator having an analog comparator first input configured to receive an analog input voltage, an analog comparator second input configured to receive the analog multiplexer output and the analog comparator configured to output a comparator voltage output and a logic loop coupled to the analog comparator and configured to receive the comparator voltage output and configured to output the logic signal, wherein the logic signal represents a linearized digital word.

Abstract: A controllable temperature coefficient bias (CTCB) circuit is disclosed. The CTCB circuit can provide a bias to an amplifier. The CTCB circuit includes a variable with temperature (VWT) circuit having a reference circuit and a control circuit. The control circuit has a control output, a first current control element and a second current control element. Each current control element has a “controllable” resistance. One of the two current control elements may have a relatively high temperature coefficient and another a relatively low temperature coefficient. A controllable resistance of one of the current control elements increases when the controllable resistance of the other current control element decreases. However, the “total resistance” of the current control circuit remains constant with a constant temperature. The VWT circuit has an output with a temperature coefficient that is determined by the relative amount of current that flows through each current control element of the control circuit.

Abstract: Bias circuits and methods for silicon-based amplifier architectures that are tolerant of supply and bias voltage variations, bias current variations, and transistor stack height, and compensate for poor output resistance characteristics. Embodiments include power amplifiers and low-noise amplifiers that utilize a cascode reference circuit to bias the final stages of a cascode amplifier under the control of a closed loop bias control circuit. The closed loop bias control circuit ensures that the current in the cascode reference circuit is approximately equal to a selected multiple of a known current value by adjusting the gate bias voltage to the final stage of the cascode amplifier. The final current through the cascode amplifier is a multiple of the current in the cascode reference circuit, based on a device scaling factor representing the relative sizes of the transistor devices in the cascode amplifier and in the cascode reference circuit.

Abstract: Temperature compensation circuits and methods for adjusting one or more circuit parameters of a power amplifier (PA) to maintain approximately constant Gain versus time during pulsed operation sufficient to substantially offset self-heating of the PA. Some embodiments compensate for PA Gain “droop” due to self-heating using a Sample and Hold (S&H) circuit. The S&H circuit samples and holds an initial temperature of the PA at commencement of a pulse. Thereafter, the S&H circuit generates a continuous measurement that corresponds to the temperature of the PA during the remainder of the pulse. A Gain Control signal is generated that is a function of the difference between the initial temperature and the operating temperature of the PA as the PA self-heats for the duration of the pulse. The Gain Control signal is applied to one or more adjustable or tunable circuits within a PA to offset the Gain droop of the PA.

Abstract: Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit and stacked transistors standby current during operation in the standby mode and to reduce impedance presented to the gates of the stacked transistors during operation in the active mode while maintaining voltage compliance of the stacked transistors during both modes of operation.

Abstract: Integrated circuits (ICs) that avoid or mitigate creation of changes in accumulated charge in a silicon-on-insulator (SOI) substrate, particularly an SOI substrate having a trap rich layer. In one embodiment, a FET is configured such that, in a standby mode, the FET is turned OFF while maintaining essentially the same VDS as during an active mode. In another embodiment, a FET is configured such that, in a standby mode, current flow through the FET is interrupted while maintaining essentially the same VGS as during the active mode. In another embodiment, a FET is configured such that, in a standby mode, the FET is switched into a very low current state (a “trickle current” state) that keeps both VGS and VDS close to their respective active mode operational voltages. Optionally, S-contacts may be formed in an IC substrate to create protected areas that encompass FETs that are sensitive to accumulated charge effects.

Abstract: Temperature compensation circuits and methods for adjusting one or more circuit parameters of a power amplifier (PA) to maintain approximately constant Gain versus time during pulsed operation sufficient to substantially offset self-heating of the PA. Some embodiments compensate for PA Gain “droop” due to self-heating using a Sample and Hold (S&H) circuit. The S&H circuit samples and holds an initial temperature of the PA at commencement of a pulse. Thereafter, the S&H circuit generates a continuous measurement that corresponds to the temperature of the PA during the remainder of the pulse. A Gain Control signal is generated that is a function of the difference between the initial temperature and the operating temperature of the PA as the PA self-heats for the duration of the pulse. The Gain Control signal is applied to one or more adjustable or tunable circuits within a PA to offset the Gain droop of the PA.

Abstract: Devices and methods for improving voltage handling and/or bi-directionality of stacks of elements when connected between terminals are described. Such devices and method include use of symmetrical compensation capacitances, symmetrical series capacitors, or symmetrical sizing of the elements of the stack.

Abstract: A controllable temperature coefficient bias (CTCB) circuit is disclosed. The CTCB circuit can provide a bias to an amplifier. The CTCB circuit includes a variable with temperature (VWT) circuit having a reference circuit and a control circuit. The control circuit has a control output, a first current control element and a second current control element. Each current control element has a “controllable” resistance. One of the two current control elements may have a relatively high temperature coefficient and another a relatively low temperature coefficient. A controllable resistance of one of the current control elements increases when the controllable resistance of the other current control element decreases. However, the “total resistance” of the current control circuit remains constant with a constant temperature. The VWT circuit has an output with a temperature coefficient that is determined by the relative amount of current that flows through each current control element of the control circuit.

Abstract: An RF switch to controllably withstand an applied RF voltage VSW, or a method of fabricating such a switch, which includes a string of series-connected constituent FETs with a node of the string between each pair of adjacent FETs. The method includes controlling capacitances between different nodes of the string to effectively tune the string capacitively, which will reduce the variance in the RF switch voltage distributed across each constituent FET, thereby enhancing switch breakdown voltage. Capacitances are controlled, for example, by disposing capacitive features between nodes of the string, and/or by varying design parameters of different constituent FETs. For each node, a sum of products of each significant capacitor by a proportion of VSW appearing across it may be controlled to approximately zero.

Abstract: Bias circuits and methods for silicon-based amplifier architectures that are tolerant of supply and bias voltage variations, bias current variations, and transistor stack height, and compensate for poor output resistance characteristics. Embodiments include power amplifiers and low-noise amplifiers that utilize a cascode reference circuit to bias the final stages of a cascode amplifier under the control of a closed loop bias control circuit. The closed loop bias control circuit ensures that the current in the cascode reference circuit is approximately equal to a selected multiple of a known current value by adjusting the gate bias voltage to the final stage of the cascode amplifier. The final current through the cascode amplifier is a multiple of the current in the cascode reference circuit, based on a device scaling factor representing the relative sizes of the transistor devices in the cascode amplifier and in the cascode reference circuit.

Abstract: An apparatus for generating a steady state positive voltage (PVS) signal and a steady state negative voltage (NVS) signal is presented. The apparatus includes a bias signal generation module for generating a steady state reference voltage signal (RVS) based on a varying supply voltage signal (VDD), the RVS having a voltage level less than the PVS. The apparatus further includes a positive signal generation module (PSGM) generating the PVS, the PSGM including a first capacitor, the PSGM employing the first capacitor to generate a portion of the PVS based on the RVS. The apparatus further includes a negative signal generation module (NSGM) generating the NVS, the NSGM including a second capacitor, the NSGM employing the second capacitor to generate a portion of the NVS based on the RVS.

Abstract: Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit and stacked transistors standby current during operation in the standby mode and to reduce impedance presented to the gates of the stacked transistors during operation in the active mode while maintaining voltage compliance of the stacked transistors during both modes of operation.

Abstract: Modified silicon-on-insulator (SOI) substrates having a trap rich layer, and methods for making such modifications. The modified regions eliminate or manage accumulated charge that would otherwise arise because of the interaction of the underlying trap rich layer and active layer devices undergoing transient changes of state, thereby eliminating or mitigating the effects of such accumulated charge on non-RF integrated circuitry fabricated on such substrates. Embodiments retain the beneficial characteristics of SOI substrates with a trap rich layer for RF circuitry requiring high linearity, such as RF switches, while avoiding the problems of a trap rich layer for circuitry that is sensitive to accumulated charge effects caused by the presence of the trap rich layer, such as non-RF analog circuitry and amplifiers (including power amplifiers and low noise amplifiers).

Abstract: Integrated circuits (ICs) that avoid or mitigate creation of changes in accumulated charge in a silicon-on-insulator (SOI) substrate, particularly an SOI substrate having a trap rich layer. In one embodiment, a FET is configured such that, in a standby mode, the FET is turned OFF while maintaining essentially the same VDS as during an active mode. In another embodiment, a FET is configured such that, in a standby mode, current flow through the FET is interrupted while maintaining essentially the same VGS as during the active mode. In another embodiment, a FET is configured such that, in a standby mode, the FET is switched into a very low current state (a “trickle current” state) that keeps both VGS and VDS close to their respective active mode operational voltages. Optionally, S-contacts may be formed in an IC substrate to create protected areas that encompass FETs that are sensitive to accumulated charge effects.

Abstract: Devices and methods for improving voltage handling and/or bi-directionality of stacks of elements when connected between terminals are described. Such devices and method include use of symmetrical compensation capacitances, symmetrical series capacitors, or symmetrical sizing of the elements of the stack.

Abstract: An RF switch to controllably withstand an applied RF voltage Vsw, or a method of fabricating such a switch, which includes a string of series-connected constituent FETs with a node of the string between each pair of adjacent FETs. The method includes controlling capacitances between different nodes of the string to effectively tune the string capacitively, which will reduce the variance in the RF switch voltage distributed across each constituent FET, thereby enhancing switch breakdown voltage. Capacitances are controlled, for example, by disposing capacitive features between nodes of the string, and/or by varying design parameters of different constituent FETs. For each node, a sum of products of each significant capacitor by a proportion of Vsw appearing across it may be controlled to approximately zero.

Abstract: A non-linear converter comprising a non-linear voltage divider having a plurality of resistors representing a non-linear transfer function, an analog multiplexer having analog multiplexer inputs coupled to the non-linear voltage divider and configured to output an analog multiplexer output, the analog multiplexer chooses one of the plurality of resistors based on a logic signal and the non-linear transfer function, an analog comparator having an analog comparator first input configured to receive an analog input voltage, an analog comparator second input configured to receive the analog multiplexer output and the analog comparator configured to output a comparator voltage output and a logic loop coupled to the analog comparator and configured to receive the comparator voltage output and configured to output the logic signal, wherein the logic signal represents a linearized digital word.