The Raleigh-Hellholes reciprocity theorem Essay Example

source refers to its directional (angular) dependence. The power pattern, which is a trace of the received power at a constant radius, is also called the radiation pattern of a directional antenna (Figure 2). It describes the relative strength of the radiated field in different directions at a constant distance. Additionally, the radiation pattern serves as a reception pattern, as it also describes the antenna's receiving properties.

The radiation pattern is typically measured as a two-dimensional slice of the three-dimensional pattern, either in the horizontal or vertical planes. These measurements are usually presented in either a rectangular or polar format. Polar coordinate systems are widely used for this purpose. In a polar-coordinate graph, points are located by projecting them along a rotating axis (radius) until they intersect with one of several concentric circles. In order for the propagation to be effective, the frequency of both the transmitting and receiving antenna must be matched.

Due to the size of the antenna, the transmitter's frequency remains at 600 Maze. This gives us a wavelength of 0.5 m or 50 cm. Initially, the input power for the directional antenna is set at 110 db, but we have included a 20 db attenuator at the input point to reduce some of this power. On the receiver side, we measure the received power for both omni directional and directional antennas across angles ranging from 0 to 360 degrees with increments of 5 degrees. These measurements allow us to determine the radiation pattern in the azimuth plane, which is similar to a top view observed from above like that seen by a bird.