# Antenna Formulas and Resonance

BASIC ELECTRONICS ANTENNA FORMULAS

Basic electronics formulas are included to aid you in solving any electronics problem that you may encounter. These formulas are for antennas, resonance, transistors, vacuum tubes, wavelength, and radar. Additional formulas may be found in the appropriate NEETS module.

Antennas

An antenna is a conductor or a group of conductors used either for radiating electromagnetic energy into space or collecting it from space or both. Antenna gain remains the same for the antenna whether it is transmitting or receiving.

Antenna gain (G) can be described as the effectiveness of a directional antenna in a particular direction, compared to a standard or reference antenna. Some antenna formulas are shown below:

WARNING

Rf voltages may be induced in ungrounded metal objects such as wire guys, wire cables (hawsers), handrails, or ladders. You could receive a shock or rf burn if you  come  in  contact  with  these  objects.  Obtain  proper  permission  prior  to  going topside or "working aloft." Rf  burns  are  usually  deep,  penetrating,  and  third  degree.  They  must  heal from the inside out. If you are burned, seek medical attention. A person in an RF field will usually have a body temperature rise. The eyes and reproductive organs are especially susceptible to RF energy.

Read and heed all warning signs! You can find more information about antennas in NEETS, Module 10, Introduction to Wave Propagation, Transmission Lines, and Antennas.

RESONANCE is a condition that exists in a circuit when inductance, capacitance, and the applied frequency are such that inductive reactance and capacitive reactance cancel each other. Formula for resonant frequency (fr).

NOTE: The formula for resonance is the same for series or parallel circuits when XL = X