An RF circuit having a transcoupler, a multifunctional RF-circuit element that can operate both as an impedance inverter and as a signal coupler. When connected to a fixed load impedance, the transcoupler can also operate as an impedance transformer. The impedance-transformer/inverter functionality of the transcoupler can be used, e.g., to modulate the load of a power amplifier. The signal coupler functionality of the transcoupler can be used, e.g., to generate a corresponding feedback signal indicative of phase and/or amplitude distortions in the amplifier. The use of various embodiments of the transcoupler in an RF circuit can be advantageous, for example, because the transcoupler has a lower insertion loss than a cascade consisting of a prior-art impedance inverter and a prior-art directional coupler, occupies a relatively small area on the printed circuit board, and helps to reduce the per-unit fabrication and operating costs.