Antennas in Electronic Communication Articles: Antenna Definition: The Antenna Definition is a quick review of impedance matching (basic transformer theory) and resonant circuits. It was pointed out that maximum power…
Parabolic Antenna: The Parabolic Antenna is a plane curve, defined as the locus of a point which moves so that its distance from another point (called the focus) plus its…
Effects of Antenna Height: At low and medium frequencies, where wavelengths are long, it often becomes impracticable to use an antenna of resonant length. The vertical antennas used at those…
Effects of Ground on Antenna Performance: The Effects of Ground on Antenna Performance on a detailed discussion of the interaction (see Figure 9-11). Ungrounded Antennas: As was know, when a radiation…
Sky Wave Propagation Frequency Range: Sky Wave Propagation Frequency Range is the ionosphere is the upper portion of the atmosphere, which absorbs large quantities of radiant energy from the sun,…
Noise and Frequency Modulation: Noise and Frequency Modulation is much more immune to noise than amplitude modulation and is significantly more immune than phase modulation. In order to establish the…
Theory of Frequency Modulation and Phase Modulation: Frequency Modulation and Phase Modulation is a system in which the amplitude of the modulated carrier is kept constant, while its frequency and…
Sample and Hold Circuit: Four basic sample and hold circuit are shown in Fig. 14.141. In these circuits a JFET is used as switch. During the sampling time the JFET…