The invention relates to a transmitting and/or receiving arrangement for portable appliances, consisting of a shielding housing of metal, containing the radio-frequency section, and an antenna, the antenna consisting of two or more antenna resonators which are parasitically coupled to one another and are essentially identically oriented in the longitudinal direction, having in each case one free resonator end and in each case one end angled via a bending edge and conductively connected to the shielding housing.
In EP-A 177 362, a wide-band antenna for portable radio appliances is described. It consists of two angled resonators of different resonant frequency. The two resonators are fed by a common line via a branch of the type of an "inverted-F antenna". The antenna resonators act independently of one another and do not form a unit. This is why the efficiency is not particularly high. The distance between the parallel legs is constant.
In U.S. Pat. No. 4,584,585, an antenna with resonators of wire angles is described. One resonator is fed at the end and forms an "inverted-L antenna". The second resonator is parasitically coupled. Although this arrangement achieves a good efficiency, the antenna has a fixed impedance and cannot be easily matched. The shape of the active antenna resonator is relatively difficult to bend and, in addition, the baseplate also exhibits a step. The bandwidth is relatively narrow.
In GB-A 2 067 842, a microstrip antenna is described which is applied to an insulating ground. Here, too, the distance between the two antenna resonators is constant. The free ends of the resonators are opposite one another. The feedpoint is close to the free end of one resonator.
"Inverted-F antennas" are known from T. Taga and K. Tsunekawa, "Performance Analysis of a Built-in Planar Inverted F Antenna for 800 MHz Band Portable Radio Units," IEEE Trans., Selected Areas in Commun., vol. SAC-5, no.5, pp. 921-929, June (1987). Such antennas are matched by varying the position of the feedpoint.