Abstract: A radio frequency transformer has the two lines which constitute it on at least four levels of a printed circuit. Two of the four levels correspond to each line. In one variant the lines are wrapped onto a cube. The levels corresponding to one line are interleaved with the levels corresponding to the other one. The transformer has two input ports, one of which is connected to ground, and two output ports. This reduces the area and therefore the cost of the circuit or provides the facility to mount other components and thus other functions.

Abstract: A radiocommunications device comprising an antenna (20) and a power amplifier (24) connected to a printed circuit (26), the device being characterized in that the mass (21) of the antenna (20) and the mass (22) of the power amplifier (24) are thermally connected.

Abstract: In a method of analyzing the spectrum of a radio communication system transmission signal having a given carrier frequency, the transmission signal is split to obtain first and second intermediate signals. A phase-shift at the given carrier frequency is applied to at least one of the intermediate signals so that at that frequency the intermediate signals have a relative phase difference of 180°. The phase-shifted intermediate signals are recombined to form a recombined signal in which the signal part transmitted at the given carrier frequency is rejected and the spectrum of the recombined signal is analyzed.