Antenna Gain - Gain Comaprison(Transfer) Method

[jegues]

Homework Statement

1) H-plane patterns of rectangular microstrip antenna, open-ended waveguide antenna and small horn antenna are measured and shown in the table below. Assuming the small horn antenna as reference antenna with a gain of $$G_{smallhorn} = 8dB$$ Obtain the gains of the other two antennas using gain-comparison method.

2) Using the gains derived in problem 1 and assuming f = 10.5GHz, obtain the effective area for the rectangular microstrip and open-ended waveguide antennas.

3) Calculate the aperture efficiency of the microstrip and open-ended waveguide antennas using the results of problem 2. (The physical aperture of the rectangular microstrip antenna is 0.8×1.25 cm^2 and the open-ended waveguide has a physical aperture size of 1×2.25 cm^2)

4) The E- and H-plane patterns of rectangular microstrip antenna and open-ended waveguide antenna are measured and the HPBWs are shown in the table below.

Use the approximate formula,

$$D = \frac{26000}{HPBW_{E} * HPBW_{H}}$$

to calculate the gains of the antennas (assuming lossless antennas). Compare these results with the results obtained in problem 1 and determine which one is more exact if they were not equal.

Homework Equations

The Attempt at a Solution

I did my solution attempt in Mathcad so that if I have to change any of the parameters I can quickly solve the problem again.

Since there is no simple way to convert my math to text or latex I've attached an image of my solution attempt below.

Questions

My calculated gains from part 1) don't seem to be lining up with the gains from part 4).

Am I correct to use the power values in Watts and not dB in part 1)?

Is the approximate formula in 4) meant for HPBW values given in radians?

 

[KataKoniK]

I would like to clarify a few things before addressing your questions. First, can you provide the table of H-plane patterns and HPBWs mentioned in the problem statement? This will help me understand the exact values you are working with. Also, in your solution attempt, can you provide more details on how you calculated the gains and effective areas for the antennas? This will help me better understand your approach and provide more accurate feedback.

To address your questions, yes, it is correct to use power values in Watts for part 1). dB is a logarithmic unit and needs to be converted back to its linear form (Watts) before performing calculations.

For part 4), the approximate formula is typically used for HPBW values given in degrees, not radians. However, you can convert radians to degrees by multiplying by 180/pi. Also, please note that the formula may not give an exact result, but it can provide a good approximation.

Without seeing the actual values and calculations, it is difficult for me to determine which solution is more accurate. However, I would suggest double-checking your calculations and making sure all parameters are consistent (e.g. using the same units for all values). Additionally, you can try using different methods or equations to calculate the gains and compare the results to see which one gives a more accurate result.

Overall, it is important to carefully check all calculations and assumptions made in your solution attempt to ensure accuracy. Also, make sure to clearly state any assumptions or approximations made in your solution so that others can understand and verify your results.