Newtons4th PSM1700 User Manual

PSM1700 PsimetriQ user manual
16-9
16.8 Insertion loss
Insertion loss is a measure of power loss due to impedance
mismatch in signal transformers that are terminated with
the design load resistance.
The secondary winding is terminated with the appropriate
load resistance and the primary is energised via a source
resistance that is equal to the resistance that should be
reflected back from the secondary (load resistance *
(turns ratio)² ). The voltage energising the series
resistance and primary winding is measured and the
voltage on the secondary is measured.
If Rs is the source resistance, the power into the
transformer is computed as:
Win = Vin² / 4 Rs
If Rl is the load resistance, the power out is computed as:
Wout = Vout² / Rl
Insertion loss then is given by:
Insertion loss = Win / Wout
= (Vin / Vout)² . Rl / 4 Rs
Insertion loss is usually expressed in dB:
= 10 log ((Vin / Vout)² . Rl / 4 Rs) dB
As a figure of merit, a lower value of insertion loss
indicates a better transformer.
To manually connect a transformer for insertion loss
measurement, fit the appropriate source resistance in
series with the primary winding then connect the PsimetriQ

Newtons4th PSM1700 Specifications

General

Brand	Newtons4th
Model	PSM1700
Category	Measuring Instruments
Language	English