Broad band coupler for testing communication devices, such as mobile phones, antenna signals, to ensure bandwidth regulations are not broken and where the device under test does not have to be coupled directly to the tester

摘要

Antenna coupler for use with communications devices couples the device under test (2) antenna to a tester (11). Antenna coupler has an inner cylinder (6) of conducting material in which an antenna (5) in attached at a selected depth along the axis of the inner cylinder (6). The inner cylinder has constant inner and outer diameter along a length that is at least as long as the selected depth. Over a second length (8) the outer diameter of the inner cylinder reduces to a first diameter equal to that on an attached antenna to form a coaxial transfer conductor with a characteristic impedance Zin. An outer conducting cylinder (7) narrows over the same length as the inner cylinder the outer cylinder narrows in order to maintain a constant input impedance Z0in. The transfer section formed by narrowing inner and outer cylinders has a characteristic impedance Z0out. The inner and outer coaxial cylinder arrangement acts as a HF connection between antenna (5) and test device (11).