BS IEC 62047-41:2021 pdf free download – Semiconductor devices – Micro- electromechanical devices Part 41: RF MEMS circulators and isolators.
d) The network analyser should be pre-set and set up to the standard S-parameters measurement class, where selecting the transmission measurements (S21, S32 and S13):
1) Specify the frequency range of the signal source, which is the span of frequency for making a device measurement, including start frequency, stop frequency, number of measurement points, etc.;
2) Specify the frequency sweep type of the signal source, using linear frequency sweep type typically;
3) Specify the power level of the signal source to proper value;
4) Specify the display format, usually using “Log Mag” display format.
e) Perform measurement:
1) Scale the displayed measurement for optimum viewing;
2) Read the S-parameter (S21, S32 and S13) values. Each parameter values at each frequency point are the insertion loss: Ljns(21) = S21, = S32 and Lpfls(13) = S13.
5.2.5.2 Method B): with the 2-port network analyser, the measurement procedures are as follows:
a) The RF MEMS circulator/isolator should be suitably packaged and mounted on a test fixture;
b) The test fixture, the network analyser, cable, and connectors should be calibrated before performing measurement;
c) The test fixture should be connected to the network analyser using the test cable with 50 0 connectors. For circulators, connected as shown in Figure 6 a); for isolators, connected as shown in Figure 7;
d) The network analyser should be pre-set and set up to the standard S-parameters measurement class, where selecting the transmission measurements (S21):
1) Specify the frequency range of the signal source, which is the span of frequency for making a device measurement, including start frequency, stop frequency, number of measurement points, etc.;
2) Specify the frequency sweep type of the signal source, using linear frequency sweep type typically;
3) Specify the power level of the signal source to proper value;
4) Specify the display format, usually using “Log Mag” display format.
e) Perform measurement:
1) Scale the displayed measurement for optimum viewing;
2) Read the S-parameter (S21) values. Each parameter values at each frequency point are the insertion loss:
f) Measuring insertion loss LflS(l3):
The circulator should be connected as shown in Figure 6 b). Repeating procedures d) to e), each parameter values of S21 at each frequency point are the insertion loss: Ljfls(13) = S21.
g) Measuring insertion loss
The circulator should be connected as shown in Figure 6 c). Repeating procedures d) and e),
each parameter values of 2l at each frequency point are the insertion loss: LIfls(32) = 2l•
5.2.6 Specified conditions
The specified conditions are as follows:
a) frequency range;
b) input power level.
5.3 Isolation
5.3.1 Purpose
To measure the isolation under specified conditions.
5.3.2 Circuit diagram
With 4-port network analysers, the measuring circuit diagram of the isolation measurement of circulators is shown in Figure 4, and the measuring circuit diagram of the isolation measurement of isolators is shown in Figure 5.
With 2-port network analysers, the measuring circuit diagram of the isolation measurement of circulators is shown in Figure 6, and the measuring circuit diagram of the isolation measurement of isolators is shown in Figure 7.
5.3.3 Principle of measurement
When the incident power is applied to the circulator/isolator, the amplitude of the power attenuation, in the reverse direction of signal transmitted, is treated as the isolation. The isolation of the circulator/isolator is obtained from the measured S-parameter. The isolation is normally expressed in decibels (dB) and obtained by Formulas (4) to (6).