VHF / UHF Filters and Multicouplers: Application of Air Resonators

Chapter 2

Measurements in HF

2.1. Material

No HF laboratory can exist without a network analyzer. All technicians have their own; it is the characteristic and personal device of the profession and it is indispensible, though it cannot do everything itself because it works at low level. Once a prototype is developed, at some point its power behavior must be studied to verify that it satisfies the specifications. This is the role of the power bench, which itself is also an essential element of the laboratory. Given its cost, its usage restrictions and working rate, the power bench forms a part of the laboratory’s collective equipment, and constitutes its most significant investment. When possible, it is located inside a Faraday cage, in order to shield the equipment to be tested from the external radiation of a place usually extraordinarily polluted by radiocommunication emitters in rampant proliferation.

On the other hand, we are often led to possess several benches in order to be able to treat multiple cases simultaneously at different frequency bands.

2.2. The power bench

2.2.1. The measurements to carry out

The measurements performed at the bench may be separated into two main categories: on the one hand, those whose goal is to verify the correct sizing of the prototype and thus its capacity to work for a long time at maximum power, and on the other, those which make it possible to ensure that it will not pollute the hertzian space beyond the limits authorized by the regulatory ...