An integrated circuit device is provided. In some examples, the integrated circuit device includes a first amplifier path, a second amplifier path coupled in parallel with the first amplifier path, a matching network coupled to the first amplifier path and the second amplifier path, and an antenna coupled to the matching network. In some such examples, the first amplifier path includes a first differential power amplifier coupled to the matching network, and the second amplifier path includes a second differential power amplifier coupled to the matching network. The integrated circuit device may further include a controller coupled to selectively enable the first amplifier path to provide a transmitter output power within a first range and to selectively enable the second amplifier path to provide a transmitter output power within a second range that is different from the first range.

A radio frequency (RF) signal transceiver is provided. The RF signal transceiver includes a first transformer, a signal transceiving processor, a signal receiving amplifier, and a signal transmitting amplifier. The first transformer is coupled to an antenna through a first end of a primary side, and two endpoints of a secondary side of the first transformer receive and transmit a pair of differential signals. The signal transceiving processor receives a pair of input differential signals from the secondary side of the first transformer and generates a pair of processed differential signals. The signal receiving amplifier is coupled to the signal transceiving processor and is configured to receive and amplify the pair of processed differential signals. The signal transmitting amplifier is coupled to the secondary side of the first transformer and provides a pair of transmission differential signals to the secondary side.

A radio frequency (RF) signal transceiver is provided. The RF signal transceiver includes a first transformer, a signal transceiving processor, a signal receiving amplifier, and a signal transmitting amplifier. The first transformer is coupled to an antenna through a first end of a primary side, and two endpoints of a secondary side of the first transformer receive and transmit a pair of differential signals. The signal transceiving processor receives a pair of input differential signals from the secondary side of the first transformer and generates a pair of processed differential signals. The signal receiving amplifier is coupled to the signal transceiving processor and is configured to receive and amplify the pair of processed differential signals. The signal transmitting amplifier is coupled to the secondary side of the first transformer and provides a pair of transmission differential signals to the secondary side.

A testing system includes: a signal generator arranged to generate a testing signal; a dividing circuit coupled to the signal generator for providing a plurality of input signals according to the testing signal; and a plurality of power-amplifier chips coupled to the dividing circuit for being tested by generating a plurality of output signals for a predetermined testing time according to the plurality of input signals respectively.

The present disclosure provides an inductive magnetic sensor, which includes a signal pre-amplifying measurement circuit, a feedback loop, a magnetic core and coil group, a low-noise autozero processing circuit, and an output protection module. The magnetic core and coil group is electrically connected between the signal pre-amplifying measurement circuit and the feedback loop, the signal pre-amplifying measurement circuit comprises the low-noise autozero processing circuit, and the feedback loop and the low-noise autozero processing circuit are electrically connected to the output protection module respectively. By introducing the resonant notch filter, it may extend the passband to the low frequency, and extend the low-frequency characteristic of the magnetic sensor, to obtain a better low-frequency magnetic sensor. The present disclosure further provides an electromagnetic prospecting equipment.

An amplifier includes a first coil coupled to at least one input node. The amplifier further includes second and third coils. A first terminal of the second coil is coupled to a source terminal of a first transistor, while a second terminal of the second coil is coupled to a source terminal of a second transistor. A third coil includes first and second terminals coupled to gate terminals of the first and second transistors, respectively. Responsive to receiving an input signal, the first coil electromagnetically conveys the signal to the second and third coils.

An apparatus includes a transceiver circuit, a series capacitor, and a shunt switch. The transceiver circuit may comprise a transmit chain including an output matching network and a receive chain including an input matching network. An output of the output matching network may be connected directly to an input/output of the transceiver circuit. The series capacitor may be connected between an input of the input matching network and the output of the output matching network. The shunt switch may be connected between the input of the input matching network and a circuit ground potential of the transceiver circuit.

An integrated circuit device is provided. In some examples, the integrated circuit device includes a first amplifier path, a second amplifier path coupled in parallel with the first amplifier path, a matching network coupled to the first amplifier path and the second amplifier path, and an antenna coupled to the matching network. In some such examples, the first amplifier path includes a first differential power amplifier coupled to the matching network, and the second amplifier path includes a second differential power amplifier coupled to the matching network. The integrated circuit device may further include a controller coupled to selectively enable the first amplifier path to provide a transmitter output power within a first range and to selectively enable the second amplifier path to provide a transmitter output power within a second range that is different from the first range.

A transistor amplifier includes at least one differential pair of transistors and a plurality of transformers having a primary winding and a tapped secondary winding. The secondary winding is connected across emitters or sources of each transistor pair. The tap of each secondary has a current source. The primary windings of the plurality of transformers are connected in series. The transistor bases or gates are alternating current (AC) grounded. The collector or drain terminal pairs are connected in parallel. The transistor amplifier exhibits improved input impedance and improved linearity.

Disclosed is a 5G (5.sup.th generation) or pre-5G communication system for supporting a data transmission rate higher than that of a 4G (4.sup.th generation) communication system such as long-term evolution (LTE). A transmission device comprises: a first amplification unit having a common source structure, including cross coupled capacitors, and amplifying an input signal; a second amplification unit, having a common gate structure, for amplifying a signal output from the first amplification unit; and a first removal unit which is connected to output terminals of the first amplification unit and input terminals of the second amplification unit and which removes at least one portion of second harmonics. The first removal unit can offset, with respect to a fundamental frequency, at least some of parasitic capacitance generated from the output terminals of the first amplification unit and the input terminals of the second amplification unit, and can ground a signal having a secondary harmonic frequency with respect to the secondary harmonic frequency.