The antenna factor, usually specified by antenna manufacturers provides the relationship between the open circuit voltage at the antenna terminals and the E wave impinging on the antenna. In other words, Antenna Factor = AF = Abs(E field)/abs(Open circuit voltage). Therefore the absolute value of the received voltage at the antenna terminals is given by Absolute value of the electric field divided by the antenna factor. In many cases this is expressed in dB terms. In this case absolute value of the open circuit voltage in dB = absolute value of the electric field in dB-the antenna factor in dB. As an example assume that: (1) The E field at the surface of the antenna is 80 dB uV/m, (2) The open circuit voltage at the circuit terminals is measured by a spectrum analyzer to be 45 dBuV, (3) The loss in the cable connecting the antenna terminals to the circuit terminals is 6.0 dB. Then AF = 80 -(45 + 6)= 29 dB.
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We are indebted to an interested visitor to our website who commented on the bondwire fusing equation provided ( as well as the calculator) about the enormous levels of fusing currents predicted by that tool.The reader also referred to a paper by IDT referring to bondwire fusing currents. In that paper the bondwire fusing current presented for gold wire and based on the classical Preece equation was as follows: A 2 mil diameter gold wire was shown to have a fusing current of 0.92 Amps. These specifications for the gold wire were input into the SPG fusing current calculator and it was found that there was close agreement with the Preece equation. However, there was one interesting difference. In the SPG calculator ( based on the May equation) a time factor was required. The time required in the SPG calculator was 100 milliseconds for the wire to melt. There appears to be no time factor in the Preece equation that is based on a rms or dc current. To explain this seeming discrepancy we have to argue that if the amount of heat required to melt the wire is calculated using standard Thermodynamics then we find the heat in Joules that does the damage. Now 1 Joule is 1 Watt . second. Thus time gets involved immediately. We could have a huge wattage in the wire but if the time is very small then the melting energy would be very small. Therefore time should be considered in the equation somewhere. Debatable point?
RF power amplifiers are an important part of the communications chain in any wireless communication system. It is therefore important to understand how an RF Power Amplifier is specified. There are many scattered accounts of RFPA specifications across the web. Signal Processing Group Inc., has recently released a brief paper which attempts to bring the various specifications of a RF Power Amplifier together and tabulate them along with brief descriptions. This paper is available on the Signal Processing Group Inc., website from the ” Free articles ….” link for interested users.
Antenna specifications are an important part of the design and development of antennas of any kind. Signal Processing Group Inc., has recently released a brief paper on this is important topic. The paper can be accessed by going to the Signal Processing Group Inc., website and selecting the free articles link. Also check out the book ( cover shown below) on impedance matching, VSWR and other related topics.by following the link.