An illustration of the measurement setup is shown in Figure 7, where a vector network analyzer (VNA) equipped with a vertically polarized biconical antenna
(Tx) and a vertically polarized horn antenna (Rx) was utilized.
To measure the Polarization of receiving electromagnet waves, dual polarization Omni antenna and biconical antenna
were installed as the figure 13.
Moreover, because they represent the two-dimensional analogue of a biconical antenna
they possess a broad bandwidth.
Using several feed probes, higher-order modes were excited in a biconical antenna
Two equipotential surfaces of equal and opposite potentials are thus generated defines the profile of the biconical antenna
. Both of these surfaces can be realized by perfect electric conductors with an appropriate total surface charge such that the potential distribution external to the surface remains unchanged.
In order to measure the power density of the radiated emission received at any arbitrary location [r.sub.3], a biconical antenna
Schwarzbeck EFS921 was connected to a second port of the DSO.
Frequency Band 2.8GHz-5 GHz Number of 1601 frequency points Antenna Biconical antenna
(Electrometrics EM-6116) Transmitter Power 20 dBm Dynamic Range > 100dB Position in the 12 positions every 3cm transverse plane ([lambda]/2 at 5GHz) Positions along the From 50 m to 202 m every 4 m longitudinal axis From 202 m to 500 m every 6 m Number of acquisitions 5 at each position
Emissions and Susceptibility Tests Equipment Description Receiver/Spectrum Analyzer 10 kHz to 1 GHz; frequency range covers [+ or -]90% of the problems for a non-RF EUT Low-noise preamp if spectrum analyzer is used Biconical Antenna
Usable from 10 MHz to 500 MHz; selection based on EUT's problem frequencies.
The lower frequency band uses a biconical antenna
while the higher frequency band uses a log-periodic antenna (although the range from 30 to 1000 MHz can also be handled with a single broadband antenna).
An interesting variation of the biconical antenna
involves the use of meander-line arrays.
The radiation patterns show that in the H-plane the antenna has nearly omnidirectional radiation pattern at lower frequencies (from 1 GHz to 5 GHz), while the E-plane radiation pattern shows a typical figure-of-eight at the frequency of 1GHz, which is similar to a conventional dipole or to that of a biconical antenna
. Further geometries of printed antennas based on trapeziform ground are shown in Figure 19.
In order to improve or develop some biconical antenna
it is necessary to understand the evolution of electromagnetic fields inside it.