Abstract: A radio frequency circuit includes a power amplifier configured to selectively amplify one of a first radio frequency signal and a second radio frequency signal that have different bandwidths, and when the first radio frequency signal is input to the power amplifier, a first bias signal is applied to the power amplifier, and when the second radio frequency signal is input to the power amplifier, a second bias signal different from the first bias signal is applied to the power amplifier.

Abstract: A power amplifier module includes an output-stage amplifier, a driver-stage amplifier, an input switch, an output switch, an input matching circuit, an inter-stage matching circuit, an output matching circuit, and a control circuit. The input switch selectively connects one of a plurality of input signal paths to an input terminal of the driver-stage amplifier. The output switch selectively connects one of a plurality of output signal paths to an output terminal of the output-stage amplifier. The control circuit controls operations of the driver-stage amplifier and the output-stage amplifier. The input switch, the output switch, and the control circuit are integrated into an IC chip. The control circuit is disposed between the input switch and the output switch.

Abstract: A power amplification circuit can include an input impedance matching circuit associated with one or more frequency bands of a plurality of frequency bands. The power amplification circuit can include a transistor with respective input coupled to an output of the input impedance matching circuit. The power amplification circuit can include a plurality of output impedance matching circuits. Each output impedance matching circuit can be associated with a respective frequency band of the plurality of frequency bands. The power amplification circuit can include a single pole multi-throw (SPMT) switch having an input terminal connected to an output of the transistor and a plurality of output terminals. Each output terminal of the SPMT switch can be connected to a corresponding output impedance matching circuit of the plurality of output impedance matching circuits.

Abstract: A power amplifier comprising: a first amplifier; a second amplifier, wherein the first and second amplifiers are arranged in parallel; an analogue pre-distortion network; a first coupler; and a second coupler, wherein the first coupler is configured to receive an input signal, direct said input signal to the first amplifier, and direct a first pre-distortion signal to the analogue pre-distortion network, wherein the first pre-distortion signal comprises a first distortion component generated at the input of the first amplifier, and the analogue pre-distortion network is configured to receive the first pre-distortion signal and manipulate its amplitude and/or phase to obtain a manipulated first pre-distortion signal, and the second coupler is configured to direct the manipulated first pre-distortion signal to the second amplifier.

Abstract: Apparatus and methods for radio frequency front-ends are provided. In certain configurations, a radio frequency front-end includes ultrahigh band (UHB) transmit and receive modules employed for both transmission and reception of UHB signals via at least two primary antennas and at least two diversity antennas, thereby supporting both 4×4 receive MIMO and 4×4 transmit MIMO with respect to one or more UHB frequency bands, such as Band 42, Band 43, and/or Band 48. The radio frequency front-end can operate with carrier aggregation using one or more UHB carrier frequencies to provide flexibility in widening bandwidth for uplink and/or downlink communications.

Abstract: Various embodiments relate to an apparatus and a method for processing a radio signal in an electronic device. The electronic device may include: a communication processor; and a power amplifier electrically connected to the communication processor, the power amplifier including a first switch, an input port, a first output port, and a second output port, the power amplifier further including a first amplification circuit disposed on a first electrical path between the input port and the first switch, a second amplification circuit disposed on a second electrical path between the first switch and the first output port, and a third amplification circuit disposed on a third electrical path between the first switch and the second output port.

Abstract: A radio frequency module includes: a first power amplifier and a second power amplifier on a first principal surface of a module board; external-connection terminals on a second principal surface; and a first via-conductor and a second via-conductor apart from each other inside of the board. One end of the first via-conductor is connected to a ground electrode of the first power amplifier, and the other end is connected to a first external-connection terminal. One end of the second via-conductor is connected to a ground electrode of the second power amplifier, and the other end is connected to a second external-connection terminal. The second via-conductor penetrates the board in a normal direction of the first principal surface, and the first via-conductor includes columnar conductors cascaded with central axes thereof displaced in the normal direction and has no region where the columnar conductors overlap in a plan view of the board.

Abstract: A power amplifier circuit includes a power amplifier and an output matching circuit that includes a first capacitor and a switch unit. The first capacitor has a first end electrically connected to an output end of the power amplifier. The switch unit includes a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The switch unit causes the first input terminal to be connected to the first output terminal and causes the second input terminal to be connected to the second output terminal in a first operation mode of the power amplifier, and causes the first input terminal to be connected to the second output terminal and causes the second input terminal to be open or to be connected to the first output terminal in a second operation mode of the power amplifier.

Abstract: Disclosed is an electronic device including a power amplifier (PA) configured to amplify a transmission signal, a matching circuit configured to be connected with the PA and to form a load impedance, a filter configured to be connected with the matching circuit, and a control circuit configured to control a state of at least one of a bias of the PA, the matching circuit, and the filter. The control circuit may identify a network to which the electronic device is connected among a first network and a second network and may operate the matching circuit in one of a first state, a second state, and a third state based on the identified network.

Abstract: A power amplifier apparatus is provided. The power amplifier apparatus includes a number of multi-stage power amplifiers and a bias circuit configured to generate a number of bias signals (e.g., bias current or bias voltage) to control (e.g., activate or deactivate) the multi-stage power amplifiers. In examples disclosed herein, only one of the multi-stage power amplifiers is activated at a given time. In this regard, the bias circuit can generate the bias signals to collectively activate one of the multi-stage power amplifiers, while deactivating the rest of the multi-stage power amplifiers. As such, it may be possible to control a larger number of power amplifier stages based on a smaller number of bias signals. As a result, it may be possible to eliminate a biasing bump pad(s) from the power amplifier apparatus, thus helping to reduce the footprint and cost of the power amplifier apparatus.

Abstract: A radio-frequency (RF) module includes a first transistor having a base, a collector, and an emitter, a radio-frequency output transmit path coupled to the collector of the first transistor at a first end and to a radio-frequency output port at a second end, and an output matching network disposed in the radio-frequency output transmit path, the output matching network including a shunt arm coupled to ground, the shunt arm including a switch that is controllable to modify an impedance of the output matching network.

Abstract: An antenna-integrated radio frequency (RF) module includes a multilayer substrate disposed between an integrated chip (IC) and patch antennas, signal vias, and ground members. The IC is configured to generate RF signals. The signal vias are configured to connect and transmit/receive the RF signals from each of the patch antennas to the IC. The ground members are disposed on an outer surface layer and intermediate surface layers of the multilayer substrate to surround each of the patch antennas and the signal vias.

Abstract: In accordance with one embodiment, an apparatus includes a first amplifier having a noninverting input, an inverting input and an output. The noninverting input is coupled to a first ground reference. The inverting input is coupled to an output of an external sensor. The apparatus also includes a second amplifier having a noninverting input, an inverting input and an output. The noninverting input is coupled to the first ground reference. The inverting input is coupled to the power supply through a first variable capacitor and to the second ground reference through a second variable capacitor. The output is coupled to the inverting input of the first amplifier. The external sensor is coupled to a third ground reference, and the first amplifier and second amplifier are coupled to the second ground reference.

Abstract: A radio frequency (RF) circuit is provided. The RF circuit may include a variety of RF filters organized into a number of filter banks and configured to support carrier aggregation (CA) in a variety of band combinations. In examples discussed herein, the RF circuit is configured to utilize separate receive and transmit filters for filtering an RF receive signal and an RF transmit signal in a time-division duplex (TDD) band, respectively. By employing separate receive and transmit filters for the TDD band, as opposed to using an integrated receive-transmit filter, it may be possible to implement the receive and transmit filters in the RF circuit with improved impedance matching, interference rejection, and insertion loss without increasing a footprint of the RF circuit.

Abstract: Embodiments of the present disclosure disclose an equalization circuit for a CATV plug-in fixed attenuator which comprises an equalizer, an equalization compensation circuit and a MCU module. The equalizer comprises a CATV plug-in fixed attenuator identification module and an equalizing module. The CATV plug-in fixed attenuator identification module is connected to the equalizing module and the MCU module. The equalization compensation circuit is connected to an output terminal of the equalizer and the MCU module. The embodiments enable identification of a changing attenuation value and compensation of the frequency response.

Abstract: Broadband power splitter. In some embodiments, a power splitter can include an input port, a first output port and a second output port. The power splitter can further include a first signal path implemented between the input port and the first output port, and a second signal path implemented between the input port and the second output port. Each of the first and second signal paths can include a variable capacitance configured to provide a plurality of capacitance values that result in different frequency responses of the respective signal path.

Abstract: A signal transceiving control structure includes a power amplifier and N control branches. The N control branches are configured to control transmission of first signals or receiving of second signals of different network standards according to different control instructions. First ends of the N control branches are respectively connected to an output end of the power amplifier, second ends of the N control branches are respectively connected to N external output ends, third ends of the N control branches are respectively connected to N external input/output ends, wherein N is a positive integer greater than 1. The power amplifier is configured to perform power amplification on the first signals.

Abstract: A semiconductor apparatus includes the following elements. A substrate includes a ground portion to which a ground potential is supplied. A semiconductor chip is mounted on the substrate and includes first and second output terminals, a first terminator, and a ground terminal. First and second amplifiers are respectively formed in first and second regions of the semiconductor chip and respectively amplify first and second input signals of first and second frequency bands and output first and second amplified signals from the first and second output terminals via first and second output wires. A first harmonic termination circuit includes a first wire which electrically connects the first terminator and the ground portion. A ground wire is disposed between the first wire and the second output wire in a plan view of a main surface of the semiconductor chip and electrically connects the ground terminal and the ground portion.

Abstract: A low noise amplifier circuit includes a first low noise amplifier including a common gate structure cascoded with a parallel common source structure to selectively amplify a band signal among first and second band signals; a second low noise amplifier including a common gate structure cascoded with a parallel common source structure to selectively amplify a band signal among third and fourth band signals; an output DPDT circuit including a first input terminal connected to the first low noise amplifier, a second input terminal connected to the second low noise amplifier, and a first output terminal and a second output terminal for selectively outputting signals input through the first input terminal and the second input terminal; and a control circuit performing an amplification control and a switching control for the first and second low noise amplifiers and the output DPDT circuit in response to a predetermined communications scheme.

Abstract: According to an embodiment of the present disclosure, disclosed is an apparatus for generating a radio frequency (RF) pulse in a magnetic resonance imaging (MRI) scanner. The apparatus for generating a radio frequency (RF) pulse in a magnetic resonance imaging scanner includes: a control module controlling a power amplifier and a signal generator; the signal generator configured to generate a signal of a predetermined waveform based on control by the control module and supply the generated signal of the predetermined waveform to the power amplifier in electromagnetic connection therewith; a power amplifier amplifying the signal supplied from the signal generator based on the control by control module and outputting the amplified signal to a coil; and the coil serving as an inductor of the power amplifier and transferring the amplified signal to the object so that an object is excited.

Abstract: Aspects of this disclosure relate to a coupler circuit configured to receive an output of a radio frequency coupler. The coupler circuit can be arranged in a daisy chain with other coupler circuits. The coupler circuit can include a switch configured to turn on based on a signal level of a direct current component of a coupler signal from another coupler circuit and pass a radio frequency component of the coupler signal when on. The coupler circuit can pass the coupler signal while a module that includes the coupler circuit is otherwise inactive.

Abstract: In one embodiment, a device includes a multi-channel capacitive sensor and a control circuit. The control circuit is configured to ground a first sense capacitor and a second sense capacitor of the multi-channel capacitive sensor. The first sense capacitor and the second sense capacitor are adapted to be connected to a drive line. The control circuit is configured to charge, by a first voltage provided on a pin of the controller, an in-series combination of a sample capacitor and the first sense capacitor while not charging the second sense capacitor by the first voltage provided on the pin of the controller. The control circuit is further configured to measure a second voltage on the pin of the controller resulting at least in part from charging the in-series combination, the second voltage providing an indication of a capacitance of the first sense capacitor.

Abstract: A PA module includes a previous stage amplification element to amplify a high-frequency signal, a posterior stage amplification element to amplify the high-frequency signal amplified by the previous stage amplification element, and a variable filter circuit arranged between the previous stage amplification element and the posterior stage amplification element and to vary a pass band and an attenuation band in accordance with a frequency band of the high-frequency signal, in which the variable filter circuit includes a filter portion and switches, the previous stage amplification element, the switches, and the posterior stage amplification element are arranged on a mounting surface of a substrate, the filter portion is stacked and arranged so as to overlap with at least one of the previous stage amplification element, the switches, and the posterior stage amplification element when the substrate is viewed in a plan view.

Abstract: A custom application-specific integrated circuit (ASIC) may provide strong signal integrity while reducing the load to a thermal system. Control and analog-to-digital conversion may be pushed into components close to the detector to maximize signal integrity. Processing functions may be performed at relatively high temperature, or the highest allowable temperatures, simplifying the system-level thermal design by not cooling components that do not require such cooling to function.

Abstract: The disclosure relates to a lock-in amplifier comprising a plurality of channels (CH1-CHN), wherein each channel of the plurality of channels (CH1-CHN) is configured to receive an input signal (Sin1-SinN) and generate at least one output signal (Sout1-SoutN), a synchronization unit (110) configured to synchronize the generated output signals (Sout1-SoutN) of the plurality of channels (CH1-CHN), an aggregation module (150) configured to receive the generated output signals (Sout1-SoutN) and generate an aggregated signal (Sagg) based on the generated output signals (Sout1-SoutN).

Abstract: A power amplifier module includes an output-stage amplifier, a driver-stage amplifier, an input switch, an output switch, an input matching circuit, an inter-stage matching circuit, an output matching circuit, and a control circuit. The input switch selectively connects one of a plurality of input signal paths to an input terminal of the driver-stage amplifier. The output switch selectively connects one of a plurality of output signal paths to an output terminal of the output-stage amplifier. The control circuit controls operations of the driver-stage amplifier and the output-stage amplifier. The input switch, the output switch, and the control circuit are integrated into an IC chip. The control circuit is disposed between the input switch and the output switch.

Abstract: A power amplification system with shared common base biasing is disclosed. A method for power amplification at a controller of a power amplification system comprising a plurality of cascode amplifier sections can include receiving a band select signal indicative of one or more frequency bands of a radio-frequency input signal to be amplified and transmitted. The method may further include biasing a common base stage of each of the plurality of cascode amplifier sections, and biasing a common emitter stage of a subset of the plurality of cascode amplifier sections.

Abstract: Aspects of this disclosure relate to a coupler circuit configured to receive an output of a radio frequency coupler. The coupler circuit can be arranged in a daisy chain with other coupler circuits. The coupler circuit can include a switch configured to turn on based on a signal level of a direct current component of a coupler signal from another coupler circuit and pass a radio frequency component of the coupler signal when on. The coupler circuit can pass the coupler signal while a module that includes the coupler circuit is otherwise inactive.

Abstract: Disclosed herein are systems, circuits, architectures and methods related to front-end architectures for wireless devices configured for uplink carrier aggregation. The disclosed front-end architectures include a first power amplifier module with filters and a second filter-less power amplifier module. The front-end architectures are configured to route signals from the filter-less power amplifier module to the first power amplifier module for filtering. This reduces the size of the second filter-less module relative to a module that utilizes its own filters, thereby reducing costs, reducing size, and/or providing additional space for other modules or other functionality to be included in a wireless device.

Abstract: Transmission and reception of communications via high frequency antenna systems employing cooled pure copper or high-temperature superconductor filters and/or amplifiers are presented. A comb linear amplifier combiner and comb limiter combiner may be modified with, for example, cryogenically cooled pure copper and/or high-temperature superconductor components, such as matching units of bandpass filters. A computer control unit may be coupled to the transmission circuit and reception circuit to control operation of one or more filters, and/or amplifiers.

Abstract: Multi-band device having multiple miniaturized single-band power amplifiers. In some embodiments, a power amplifier die can include a semiconductor substrate, and a plurality of power amplifiers (PAs) implemented on the semiconductor substrate. Each PA can be configured to drive approximately a characteristic load impedance of a downstream component along an individual frequency band signal path, such that each PA is sized smaller than a wide band PA configured to drive more than one of the frequency bands associated with the plurality of PAs. The downstream component can include an output filter.

Abstract: An operational amplifier based circuit has an operational amplifier, a feedback circuit, and a compensation circuit block. The feedback circuit is coupled between an output port and an input port of the operational amplifier. The compensation circuit block has circuits involved in stability compensation of the operational amplifier, wherein there is no stability compensation circuit driven at the output port of the operational amplifier.

Abstract: Aspects of this disclosure relate to detecting power associated with an individual carrier of a carrier aggregated signal. In an embodiment, a carrier aggregation system includes radio frequency (RF) sources, a transmission output, and a directional coupler. The RF sources, such as power amplifiers, can each be associated with a separate carrier. The transmission output can provide a carrier aggregated signal that includes an aggregation of the separate carriers associated with the RF sources. The directional coupler can provide an indication of RF power of one of the separate carriers.

Abstract: A power amplification module includes a first input terminal that receives a first transmit signal in a first frequency band, a second input terminal that receives a second transmit signal in a second frequency band having a narrower transmit/receive frequency interval than the first frequency band, a first amplification circuit that receives and amplifies the first transmit signal to produce a first amplified signal and outputs the first amplified signal, a second amplification circuit that receives and amplifies the second transmit signal to produce a second amplified signal and outputs the second amplified signal, a third amplification circuit that receives and amplifies the first or second amplified signal to produce an output signal and outputs the output signal, and an attenuation circuit located between the second input terminal and the second amplification circuit and configured to attenuate a receive frequency band component of the second frequency band.

Abstract: A technique relates to a microwave device. The microwave device includes a Josephson ring modulator, a first multimode resonator connected to the Josephson ring modulator, where the first multimode resonator is made of a first left-handed transmission line, and a second multimode resonator connected to the Josephson ring modulator, where the second multimode resonator is made of a second left-handed transmission line.

Abstract: Existing multi-band/multi-mode (MB/MM) power amplifiers (PAs) use separate signal paths for the different covered frequency bands. This results in a large degree of hardware duplication and to a large die size and cost. Solutions that achieve hardware sharing between the different signal paths of MB/MM PAs are shown. Such sharing includes bias circuit and bypass capacitors sharing, as well as sharing front-end stages and the output stage of the PA. Signal multiplexing may be realized in the transmitter or at the PA front-end while the signal de-multiplexing can be realized either in the PA output stage or at the front-end of the output stage. Such circuits can be applied with saturated and linear MB/MM PAs with adjacent or non-adjacent bands.

Abstract: A technique relates to a microwave device. The microwave device includes a Josephson ring modulator, a first multimode resonator connected to the Josephson ring modulator, where the first multimode resonator is made of a first left-handed transmission line, and a second multimode resonator connected to the Josephson ring modulator, where the second multimode resonator is made of a second left-handed transmission line.

Abstract: A communications module includes a front-end module including a common port configured to be connected to an antenna, a reception port configured to pass a reception signal, and a transmission port configured to pass a transmission signal, and a high frequency switch circuit connected to the reception port and/or the transmission port and configured to change signal routes for signals passing through the front-end module, wherein the front-end module is configured to amplify communications signals of different communications standards.

Abstract: A radio frequency circuit. In the circuit, a first directional coupler receives a second transmit signal, uses a part of the second transmit signal as a third transmit signal, directly sends the third transmit signal to a first port of a circulator, and obtains a first coupling signal from the second transmit signal; the circulator outputs the third transmit signal through a second port; an impedance tuner transmits the third transmit signal to an antenna port and transmits, to the second port of the circulator, a first input signal from the antenna port; the circulator inputs the first input signal to a second directional coupler through a third port; the second directional coupler obtains a second coupling signal from the first input signal; and a controller adjusts impedance of the impedance tuner according to the first coupling signal and the second coupling signal.

Abstract: A low frequency loss correction circuit that improves the efficiency of a power amplifier at near-DC low frequencies The low frequency loss correction circuit can include a signal error detection circuit configured to produce an error signal in response to detecting one or more frequency components of a tracking signal below a cutoff frequency that are substantially attenuated through a capacitive path. The low frequency loss correction circuit can include a drive circuit configured to convert the error signal into a low frequency correction signal, and provide the low frequency correction signal to a voltage supply line, the low frequency correction signal including at least some of the one or more frequency components of the tracking signal below a cutoff frequency that are substantially attenuated through the capacitive path.

Abstract: According to one embodiment, a high-frequency amplifier includes an active element and an output matching circuit. The active element is provided on a substrate. The active element is configured to amplify a signal having a frequency band. The active element includes a cell region. The output matching circuit is connected to the active element. The output matching circuit includes a wire, a transmission line and an output terminal. The wire includes an input end and an output end. The input end of the wire is connected to an output part of the cell region of the active element. The transmission line is provided on the substrate. The transmission line includes an input part and an output part. The input part of the transmission line is connected to the output end of the wire. The output terminal is provided on the substrate.

Abstract: The tunable bandpass filter is used for filtering an electromagnetic signal, has a system passband between a first and a second tunable cutoff frequencies, and has a first subfilter and a second subfilter connected to one another in series between an input port and an output port and being complementary to one another in the tunable bandpass filter. At least one of the first subfilter and the second subfilter being connected to operate in reflection.

Abstract: An amplification stage and a wideband power amplifier are provided. The amplification stage includes a stage input terminal, a stage output terminal, an amplifier, an input compensation network, and in output compensation network. At the stage input terminal is received a signal which is provided via the input compensation network to the amplifier. The input compensation network filters the signal to allow a wideband operation of the amplification stage around an operational frequency. The amplified signal provided by the amplifier is provided via the output compensation network to the stage output terminal. The output compensation network configured to allow a wideband operation of the amplification stage around the operational frequency with a minimal phase shift and distortion of amplitude and phase frequency response. The wideband power amplifier includes a plurality of amplification stage combined with transmission lines or their lumped element equivalents in a specific circuit topology.

Abstract: Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes: a first channel configured to receive a first input signal and a second input signal and generate a first output signal and a second output signal based at least in part on the first input signal and the second input signal; and a second channel configured to receive a third input signal and a fourth input signal and generate a third output signal and a fourth output signal based at least in part on the third input signal and the fourth input signal. A first differential signal is equal to the first input signal minus the second input signal. A second differential signal is equal to the third input signal minus the fourth input signal. The first output signal corresponds to a first phase.

Abstract: A pickup device for an electric instrument may include at least one permanent magnet to detect vibrations from the electric instrument's strings. The pickup device may further include at least one coil within a magnetic field of the permanent magnet. The coil may be coupled to one or more of a plurality of selectable filters. The pickup device may be an integrated assembly and fittable within a standard-sized pickup cavity on the electric instrument.

Abstract: An input signal amplification system comprises at least two different means of amplifying input signals in order to obtain amplified signals. It also comprises at least one means of summing amplified signals, and dynamic means of activating or deactivating one or more of the amplifying means based on input signals.

Abstract: A power amplifier may include an amplifying unit configured to amplify an input signal, an impedance varying unit connected between the amplifying unit and an output port that is for outputting an amplified signal of the input signal, and a controller configured to output a first control signal based on a level of power of the amplified input signal of the amplifying unit to control a varying of impedance of the impedance varying unit.

Abstract: The present invention provides a signal transceiver circuit including a band-stop filter, a first band-pass filter, and a second band-pass filter. The band-stop filter blocks signals between a first frequency and a second frequency for letting signals outside of the first frequency and the second frequency of the first multi-channel signal and the second multi-channel signal pass. The first band-pass filter blocks signals output by the band-stop filter outside of a third frequency and a fourth frequency for letting signals output by the band-stop filter between the third frequency and the fourth frequency pass. The second band-pass filter blocks signals outside of a fifth frequency and a sixth frequency of the first multi-channel signal and the second multi-channel signal for letting signals between the fifth frequency and the sixth frequency of the first multi-channel signal and the second multi-channel signal pass.

Abstract: An impedance matching arrangement for an amplifier includes first and second metallic transmission lines arranged on a ground plane, the first metallic transmission line being connected with a first power amplification stage of the amplifier, the second metallic transmission line being connected with a second power amplification stage of the amplifier; wherein the first and second metallic transmission lines are electrically coupled for transmitting an RF signal amplified by the first power amplification stage to the second power amplification stage.

Abstract: Circuitry includes a balanced amplifier and bias adjustment circuitry. The bias adjustment circuitry is coupled to the balanced amplifier and is configured to measure an RF termination voltage across an output termination impedance of the balanced amplifier and adjust a bias voltage supplied to the balanced amplifier based on the RF termination voltage. Notably, the RF termination voltage is proportional to a voltage standing wave ratio (VSWR) of the balanced amplifier, and thus enables an accurate measurement thereof. By using the RF termination voltage to adjust a bias voltage supplied to the balanced amplifier, overvoltage and/or thermally stressing conditions of the balanced amplifier as a result of high VSWR may be avoided while simultaneously avoiding the need for large or expensive isolation circuitry.