Terms starting with ‘I’
- Image Antenna
- An electrical mirror-image of an antenna element formed by the radio waves reflecting from a conductive surface called a ground plane, such as the surface of the earth. It is used as a geometrical technique in calculating the radiation pattern of…
- The Ohmic value of an antenna feed point, matching section or transmission line at a radio frequency. An impedance may contain a reactance as well as a resistance component.
- Input Impedance
- The impedance presented by an antenna at its terminals. The input impedance is a complex function of frequency with real and imaginary parts. The input impedance is graphically displayed using a Smith chart.
- Intermediate-field Region
- Also referred to as the Transition Zone or Near-far Field. This is the area between near and far field. However, the near-field does not suddenly end where the far-field begins. Rather, there is a transition zone between these types where both…
- A measure of power transfer from one antenna to another. This is also the ratio of the power input to one antenna to the power received by the other antenna, expressed in decibels (dB). The same definition is applicable to two-port antennas such as…
- Isotropic Antenna
- A theoretical source which radiates the same intensity of radiation in all directions. It has no preferred direction of radiation and radiates uniformly in all directions over a sphere centred on the source. Isotropic radiators are used as reference…