Question

In a communication radar system, the power is transmitted by high power pulses of repetition frequency 1KHz and time duration 1 microsec. the reflected power is separated from the incident power using an infinity directivity directional coupler (D.C) with coupling coefficient 20dB. To measure the incident power, we use a matched 15dB calibrated attenuator and a bolometer of equivalent VSWR equals 1.5 mounted in a balanced bridge driven by dc only. Three arms of the bridge use 250 ohms resistor and the ammeter current in the external circuit is changed from 25mA to 15mA to restore balance.

a. Sketch the power measurement system
b. Calculate the peak incident power at the input of the directional coupler

Answer 1

Without complete details about the voltage change across the bolometer or other relevant information about the specific characteristics of the pulse and circuit, it is not possible to precisely calculate the peak incident power in the given communication radar system.

Step-by-step explanation:

To calculate the peak incident power at the input of the directional coupler in a communication radar system, one must use the data provided about the high power pulse, repetition frequency, the duration of each pulse, and the parameters of the directional coupler and measurement devices. However, there is insufficient information in the question to provide an exact numerical answer, as the question lacks certain details such as the voltage change across the bolometer which would allow for the calculation of the incident power using the square law behavior of the bolometer for microwave power measurements.