Analysis and Design of Electronic Circuits Used in Radio Frequency

Communication systems use information to transfer information from one place to another. This paper describes the analysis and design of electronic circuits for radio frequency communication systems covering frequencies up to hundreds of megahertz. The electromagnetic wave leaving the transmitting antenna reaches the receiving antenna with one of many waves.

So theremin dreams of an electronic musical instrument with two main circuits, a tone circuit and a volume circuit. The tone circuit uses two tuning (radio frequency) oscillators, a fixed oscillator and a variable oscillator. A fixed oscillator generates waves at a static frequency. The variable oscillator can generate a series of frequencies and is connected to a vertical antenna. The signals from the fixed oscillator and the variable oscillator are mixed by a process called heterodyne. Subtract the frequency of one oscillator from the other. The difference is amplified and the final output is an audible tone

Chokes used in radio circuits fall into two categories: chokes designed for audio frequencies and other categories for radio frequencies. Generally A. F. An audio coil called a choke can have a ferromagnetic core to increase its inductance. High frequency choke (ferrite choke or choke) has a ferrite core. High frequency choke has air core. The RF coil (R.F. choke) usually has no core. In the high power service, a large amount of heat is generated by the burning magnetic field in the manufacture and damage of the coil.

In the case of an inductor, the impedance rises with frequency. In contrast to capacitors, it operates as a low frequency short circuit and a high frequency open circuit. However, the inductors are often not used in electronic circuits, as their size, their sensitivity to Paris effects (especially magnetic fields) and because they are not as close to resistors and capacitors as their ideal circuit components. This is obviously a low pass filter (ie low frequency signal passes and high frequency signal is blocked). When w << 1 / RC, wCR << 1 and the gain amplitude is about 1, the output is equal to the input. For w >> 1 / RC (wCR >> 1), the gain is zero and the output is positive. When w = 1 / RC, it is called the interrupt frequency (or cutoff frequency, or 3 dB frequency, or half power frequency or bandwidth) and the gain amplitude is ½ (2) @ 0.7