Planar radio-antenna module

摘要

There is disclosed a radio-antenna module formed on a daughterboard comprising a substrate, a radio circuit and a monopole antenna. The radio circuit is fed between two points on the monopole antenna having a predetermined relative impedance difference and neither of which points is at zero impedance (ground). The module operates well in a vertical orientation and can discriminate between right and left hand circular polarisation, making it ideal for personal navigation device and other global positioning system applications.

主权项

1. A device comprising a radio circuit and a monopole antenna, wherein the radio circuit is disposed between two points on the monopole antenna, the two points having a predetermined relative impedance difference and neither of the two points being at a zero impedance with respect to ground;
wherein the monopole antenna has a first end connected to ground, the first end having a zero impedance with respect to ground; wherein the monopole antenna has a second end, the second end having an infinite impedance with respect to ground; and wherein the radio circuit is connected to the two points on the monopole antenna, and the two points are located between the first and the second end, thus dividing the monopole antenna into three portions: a first portion between the first end of the monopole antenna and a first of the two points, a second portion between the second of the two points and the second end of the monopole, and a third portion between the two points.