PASCO WA-9316A Complete Microwave Optics System - Manual (Page 33)

Experiment Guide Teacher’s Guide
33
Teacher’s Guide
Experiment 1: Introduction to the Microwave Optics System
Notes on the Procedure
1. The meter reading does not vary with distance in an entirely predict-
able way, since the microwaves form standing waves between the
transmitter and receiver at certain distances. In addition, the meter is
not directly related to either the electric field or the intensity of the
incident beam. The meter is useful for measuring relative intensity at a
constant distance, polarization, and so on.
2. The meter reading oscillates as the distance is decreased.
3. The presence of a reflector increases the meter reading.
4. The receiver detects no signal when the transmitter and receiver are at
90° to each other.
5. The transmitter has a roughly Gaussian output distribution, with the 1/e
points at about ±20°.
There is no significant difference between the output distributions in the hor-
izontal and vertical orientations
Answers to Questions
1. The meter reading is not proportional to either the electric field or the intensity.
2. The meter reading is not proportional to either the electric field or the intensity.
3. The transmitter output is more plane wave than spherical wave, but it has characteristics of both.