Abstract: A transformer includes a first inductor and a second inductor that are coupled to each other. The first inductor includes a plurality of parallel-connected induction coils. The second inductor includes a plurality of serial-connected induction coils. At least one of the plurality of parallel-connected induction coils and at least one of the plurality of serial-connected induction coils are adjacently disposed in a coupling manner.

Abstract: Embodiments of this application relate to an integrated circuit, a chip, and a terminal, and relate to the field of circuit technologies. An example integrated circuit includes a first inductor and a second inductor. The first inductor includes a first coil, and the first coil is a loop having a first opening. The second inductor includes a second coil and a third coil that are connected in series, and the second coil has a second opening. A magnetic field direction of the second coil is opposite to a magnetic field direction of the third coil. The second coil and the third coil are nested in the first coil, and the first inductor is not in direct contact with the second inductor.

Abstract: A radio frequency circuit includes an adjustable transformer, a first-stage amplifier, and a second-stage amplifier, the first-stage amplifier is coupled to the second-stage amplifier by using the adjustable transformer, and a bandwidth of the adjustable transformer is adjustable. When the bandwidth of the adjustable transformer is adjusted, an operating frequency band of the radio frequency circuit covers an n258 frequency band and an n257 frequency band, or the n258 frequency band and an n261 frequency band.

Abstract: A transceiver includes a package substrate and a die, and a transceiver switch is disposed in the transceiver. The transceiver switch includes an antenna feedpoint, a transmit feedpoint and a receive feedpoint that are coupled to the antenna feedpoint, and a first metal connection line disposed on the package substrate, and the antenna feedpoint and the receive feedpoint are disposed at two ends of the first metal connection line. The transceiver switch further includes a first switch, a transmit pad, and a receive pad that are disposed on the die, a first terminal of the first switch is coupled to the receive pad, a second terminal of the first switch is coupled to a ground terminal of the die, the receive pad is coupled to the receive feedpoint, and the transmit pad is coupled to the transmit feedpoint.

Abstract: A radio frequency circuit includes an adjustable transformer, a first-stage amplifier, and a second-stage amplifier, the first-stage amplifier is coupled to the second-stage amplifier by using the adjustable transformer, and a bandwidth of the adjustable transformer is adjustable. When the bandwidth of the adjustable transformer is adjusted, an operating frequency band of the radio frequency circuit covers an n258 frequency band and an n257 frequency band, or the n258 frequency band and an n261 frequency band.

Abstract: A transformer based power amplifier introducing leakage inductance to extend a working bandwidth thereof and corresponding design methodology are provided. An ultra-wideband transformer comprises a primary coil, a secondary coil mutual coupling with the primary coil, a primary tuning capacitor coupled with the primary coil in parallel and a secondary tuning capacitor coupled with the secondary coil in parallel. By means of setting a self-inductance of the primary coil, a self-inductance of the secondary coil, a mutual coupling factor between the primary coil and the secondary coil, a capacitance value of the primary tuning capacitor, and a capacitance value of the secondary tuning capacitor, a 3 dB bandwidth of the transformer covers a first mutual resonated frequency and a second mutual resonated frequency formed by the transformer.