Let's look at a housing for a 30 dB gain narrow band microstrip amplifier operating in the range of 2100-2300 MHz. Our mechanical draftsman would like to use a 1.5 X 0.5 X 2.0 inch box. Will it work?

Type "1.5,.5" above, and press <Enter> to calculate the lowest order cut-off frequencies - there are two different modes. Since screen space is limited, what we show below is similar to what you'll see:

Here are the results of the first calculation:

TE10 Cutoff = 3924.333 MHz                  TE01 Cutoff = 11803.000 MHz

The next question asked of you will be:

                 Compute attenuation/in. (Y/N): ? _

Type "Y" to answer the above and press <Enter>. You'll then be asked to input the frequency. Use the high end amplifier frequency of 2300 MHz, or a higher one if there is still significant gain, and then press <Enter> once again.

Here is your simulated input of "2300" below along with the continuing output calculations:

Enter Freq (MHz): ?  2300                 TE10 Att. @ 2300.000 MHz = 14.759 dB/in.                 TE01 Att. @ 2300.000 MHz = 53.5299 dB/in.

The next question will be: