A high throw-count multiple-pole FET-based RF switch architecture that provides good RF performance in terms of insertion loss, return loss, isolation, linearity, and power handling. A common port RFC is coupled along a common path to multiple ports RFn. Embodiments introduce additional common RF path branch isolation switches which are controlled by state dependent logic. The branch isolation switches help to isolate the unused branch ports RFn and the unused portion of the common path from the active portion of the common path, and thereby reduce the reactive load attributable to such branches that degrades RF performance of the ports RFn closer to the common port RFC. The branch isolation switches can also be used to reconfigure the switch architecture for a multiplex function as well as separate switch path banks for re-configurability of purpose, tuning, or varying switch throw counts and packaging options.

An example of a signal switch includes a first transistor coupled between first and second nodes, a plurality of second transistors coupled in series between the first and second nodes, in parallel with the first transistor, a third transistor coupled between the first node and a third node, and a plurality of fourth transistors coupled in series between the first and third nodes, in parallel with the third transistor. The signal switch further includes a first shunt path including a first shunt transistor and a first inductor connected in series between a reference node and a first connection point between two of the plurality of second transistors, and a second shunt path including a second shunt transistor and a second inductor connected in series between the reference node and a second connection point between two of the plurality of fourth transistors.

An operation method of an in-band full duplex (IFD) transceiving apparatus including a receiving end, a transmitting end, a digital self-interference cancellation (DSIC) processing unit, and a digital SI cancellation unit may comprise generating, by the DSIC processing unit, signal shaping coefficients for wave shaping of a signal of the transmitting end; generating, by the DSIC processing unit, channel estimation coefficients for cancellation of a self-interference signal in a reception signal of the receiving end; forming, by the DSIC processing unit, a transmission signal based on the signal shaping coefficients; and generating, by the DSIC processing unit, a control signal for cancellation of the self-interference signal in the reception signal based on the channel estimation coefficients.

A high throw-count multiple-pole FET-based RF switch architecture that provides good RF performance in terms of insertion loss, return loss, isolation, linearity, and power handling. A common port RFC is coupled along a common path to multiple ports RFn. Embodiments introduce additional common RF path branch isolation switches which are controlled by state dependent logic. The branch isolation switches help to isolate the unused branch ports RFn and the unused portion of the common path from the active portion of the common path, and thereby reduce the reactive load attributable to such branches that degrades RF performance of the ports RFn closer to the common port RFC. The branch isolation switches can also be used to reconfigure the switch architecture for a multiplex function as well as separate switch path banks for re-configurability of purpose, tuning, or varying switch throw counts and packaging options.

The apparatus includes a first transistor having a gate/base terminal to receive a first drive control signal used for controlling a driver stage of the transceiver and a drain/collector terminal coupled to a control terminal of a switch of the transceiver. The first transistor is switched on when the first drive control signal is at a first level that enables the driver stage to amplify a first RF signal. When the first transistor is switched on, the drain/collector terminal of the first transistor outputs to a control terminal of the switch a switch control signal at a second level that enables the switch to provide a portion of the RF signal reflected by the antenna to the load.

A radio frequency (RF) front-end apparatus is provided. In examples discussed herein, the RF front-end apparatus can be configured to communicate RF signals in millimeter wave (mmWave) RF frequencies (e.g., 12 GHz). The RF front-end apparatus includes an RF front-end circuit and an antenna element. The RF front-end circuit includes a transmit path and a receive path for transmitting and receiving RF signals, respectively. The antenna element includes an input port(s) and an output port(s) that are coupled to the transmit path and the receive path, respectively. The antenna element can be configured to enable impedance matching between the input port(s) and the transmit path, as well as between the output port(s) and the receive path. As a result, it may be possible to reduce insertion losses in the RF front-end circuit, thus helping to improve performance of the RF front-end apparatus, particularly in support of mmWave communications.

A method of separating a desired signal from an undesired signal includes obtaining a total input signal comprising the desired signal and the undesired signal in a time domain occupying a time duration from time t.sub.1 to time t.sub.2 of a single symbol in the desired signal. A transform is performed of the total input signal wherein an output of the transform is a time domain signal representing the desired signal.

Methods and apparatuses to adjust isolation between I/O ports. An apparatus includes a die, a first input or output (I/O) port, a second I/O port, and a third I/O port. The second I/O port is between the first I/O port and the third I/O port. A variable capacitor is electrically connected to the second I/O port and is configurable to adjust isolation between the first I/O port and the third I/O port. A method includes performing, by a die, a first RF function via a first I/O port; tuning a variable capacitor electrically connected to a second I/O port to adjust isolation between the first I/O port and a third I/O port, the second I/O port being between the first I/O port and the third I/O port; and performing, by the die, a second RF function via a third I/O port.

First and second frequency bands used for multiband communication are both higher than or equal to about 3 GHz, and do not overlap each other. The spacing between the first and second frequency bands is less than or equal to about 10% of the lower one of the lower-bound frequency of the first frequency band and the lower-bound frequency of the second frequency band. A radio-frequency circuit includes a first antenna, a second antenna, a first multiplexer connected to the first antenna, and a second multiplexer connected to the second antenna. The first multiplexer includes a first filter with a pass band including the first frequency band, and a third filter with a pass band different from the first filter. The second multiplexer includes a second filter with a pass band including the second frequency band, and a fourth filter with a pass band that differs from the second filter.

An apparatus includes one or more field effect transistors configured as a switch. Each of the one or more field effect transistors comprises one or more source diffusions, one or more drain diffusions, and one or more gate fingers. Each of the one or more gate fingers is disposed between a source diffusion and a drain diffusion. A first electrical connection to the one or more source diffusions is made using one or more source electrodes that extend from a first end for a first length along a long axis of the source diffusions. A second electrical connection to the one or more drain diffusions is made using one or more drain electrodes that extend from a second end for a second length along a long axis of the drain diffusions. The first length of the one or more source electrodes and the second length of the one or more drain electrodes are generally selected to avoid juxtaposition of the one or more source electrodes and the one or more drain electrodes.