During my experiments on UHF and lower microwave bands I faced a problem of accurate measurement of standing wave ratio coefficient. Commercial SWR-meters are rarely available or are not precise enough on these bands or are too expensive. Thus I decided to build my own SWR-meter. But what type? From my previous experiments with directional couplers I came to the conclusion that planar directional couplers are not suitable enough for this application. They suffer from several vices and their construction is pretty complicated. Thus I was searching an inspiration elsewhere. An idea of SWR-meter which I´m going to describe in this article belongs to Paul G7EYT.
Schematic diagram of the SWR-meter is depicted in fig. 1. It can be seen that the SWR
meter consists of three main parts: directional coupler, two detectors and display unit. Directional coupler is used to decouple a piece of energy from incident and reflected wave. Detectors convert this RF energy to direct current which is thad displayed in the display unit. All these parts are further described in this chapters. Following chapters are showing my construction of the SWR meter