An antenna is said to be broadband or wideband if its highest to lowest frequency for -10 dB return loss in a single band of operation is around 2 (input characteristics). There is nothing called ideal 3dB beamwidth value and gain of any broadband antenna as it depends upon so many factors like frequency of operations, aspect ratio, applications, etc.
The biconical antenna should have 360 degrees beamwidth in the horizontal plane. In the vertical plane the beamwidth depends on the design. The length and angle of the cones should have been chosen to give the required beamwidth. This may be quite narrow, because for communications there is often not any need to send much signal up into the sky or down into the ground.
The gain will vary with the vertical beamwidth, something like gain =120/beamwidth in degrees. This is very approximate.
This relationship should be found in the introduction of almost any antenna book.
Sovan Mohanty sir thank you. Could you kindly tell me which formula can be used to do gain calculation of biconical antenna? Can you kindly provide any specific notation for gain calculation?
Malcolm White sir thank you for your explanation, Could you kindly tell me which formula can be used to do gain calculation of biconical antenna? Can you kindly provide any specific notation for gain calculation?
The gain of any antenna integrated over the entire sphere should be equal to the efficiency. A biconical antenna should be nearly 100% efficient, so the gain should integrate out to close to 1.
If the antenna has 360 degrees beamwidth in the horizontal plane then you can approximate the integration by multiplying by the 3 dB vertical beamwidth and the peak gain. If the integration is carried out with angle measured in radians then 2pi times the beamwidth times the gain is approximnately 1. The gain is approximately 1/2/pi/beamwidth.
The 3 dB beamwidth may be similar to the angle between the cones.
Read an antenna book and papers on biconical antennas. Try doing an internet search on "design of biconical antennas". Unless you are just going to copy an antenna design you will need to learn about the relationship between cone angle, cone length wavelength and beamwidth.
For this kind of problem you may try to to use the free Amanogawa software for education ..the actual biconical antenna is not in the library( but the normal symmetric dipole is available) but since this type of antenna is used since more than 80 years and also available from many EMI EMC hardware suppliers ( you can easily find names on the web) you can easily find a comparison. I am just wondering why you would like to design a new one
Dear
Please go through the chapter on "Antenna Parameter" from any antenna book. You should get a detailed idea of how to do it.
Gain = Efficiency * Directivity
As per definition of Directivity by IEEE, “the ratio of the radiation
intensity in a given direction from the antenna to the radiation intensity
averaged over all directions" - is directivity.
So, Directivity = Radiation Intensity in the Direction of Maximum Radiation/ Average Radiation Intensity over all direction
Average Radiation Intensity = Radiated Power/ (4*Pi)
Radiation Intensity is defined by IEEE as, “the power radiated from an antenna
per unit solid angle"
Hope this helps.
I think Chapter 2 of the book titled "ANTENNA THEORY
ANALYSIS AND DESIGN" by Constantine A. Balanis (I use the 3rd edition) can give you excellent numerical and procedural example. Other antenna books will also help.
Thank u.