how to understand the content of s2p file(MRFE6VS25N)

[530586517]

the LDMOS MRFE6VS25N, in the datasheet，at 1030MHz,G=22.5dB；but in it's s2p file , at 1030MHz, S21=2.5917, s21 is not equal to G ……how to understand ?

[LPP]

1.
S2P header describes conditions used to measure S-parameters

! MRFE6VS25NR1 S-Parameters

! Vdd = 50 Vdc, Idq = 150 mA

# hz S ma R 6.8

S2P data was measured at 6.8 Ohm reference source and load impedances. Please note that 6.8 Ohm impedance is not a matched source/load impedance. Thus, S21 is less than a gain in a matched design.

S2P can be used to calculate MAG (maximum stable gain) and MSG (maximum stable gain).
https://www.microwaves101.com/encyclopedias/stability-factor

2.
The datasheet provides Gps power gain value as measured in NXP 1030 MHz narrowband test circuit.

Please note that datasheet Gps is not a small-signal gain. Gps has been measured at specified high power level. Large signal gain is not equal to those gain values which can be calculated from S-parameters.

You can find more information about the topic:
https://www.nxp.com/docs/en/application-note/AN1526.pdf

Have a great day,

Pavel
TIC

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[530586517]

Dear sir or ma'am，thanks for your suggestions. May i have you attention for three questions？

On the page 23/24 of the datasheet of MRFE6VS25N，there is a reference circuit component layout which contains some kinds of microstrip at 1030MHz.

In conditions of input and output impedance matching via changing values or locations of capacitors or inductors ，can I decrease the width or length of microstrips ? eg. Z6、Z7 and Z11 ....

For narrowband or single frequency application，the impedance matching can be realized easily with less components. Is that right?

At the bottom of the reference circuit component layout，there are some microstrips with nothing components on both sides of cut out area. What is the functions of them？

Look forward to your reply，thank you !

[LPP]

>can I decrease the width or length of microstrips ?

Microstrips are parts of the impedance matching network. Changing the width or length of microstrips would require modification of other components (values or locations of capacitors or inductors). Full redesign of the circuits will be needed.

>For narrowband or single frequency application，the impedance matching can be realized easily with less components.

Indeed. Narrowband design can be implemented with less components.

>At the bottom of the reference circuit component layout...

These areas are provided for optional gate and drain bias circuit design. The main difference is that the connection points are located closer to the  transistor pads.
Have a great day,

Pavel
TIC