Category: Antenna Fundamental

A Hertz Antenna Impedance value may be specified for a half-wave antenna thus constructed. Generally, the impedance at the ends is maximum, while that at the input is minimal. Consequently, the impedance value varies from a minimum value at the generator to a maximum value at the open ends. An impedance curve for the half-wave antenna is shown in Figure 1. Notice that the line has different impedance values for different points along its length. The impedance values for half-wave antennas vary from about at the open ends to at…

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Any antenna having a physical length that is the one-half wavelength of the applied frequency is called a Hertz antenna. Hertz antennas are predominately used with frequencies above 2 MHz. It is unlikely that a Hertz antenna will be found in applications below 2 MHz because at these low frequencies this antenna is physically too large. Usually, at frequencies below 2 MHz, a Marconi type of antenna is used. This is a quarter-wavelength antenna with the ground reflection acting as the other quarter wavelength. Development of the Hertz Antenna When…

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