Help on RF amp please

[IanM]

Hi,

I have been working on an RFID project that uses a power booster from a
Melexis cookbook.

http://www.melexis.com/Assets/MLX90121_Cookbook_5100.aspx

Warning it is a 1MByte download. I also posted the schematic on abse.

The booster is on page 5.

I would like to know how to calculate the power gain and why it is dependant
on the voltage at the top of L3?

Any help on how this works would be appreciated.

Thanks,

IanM

 

[Andrew Holme]

"IanM" <nobody@no_where.co.uk> wrote in message
news:01407bea$0$22571$c3e8da3@news.astraweb.com...

Hi,

I have been working on an RFID project that uses a power booster from a
Melexis cookbook.

http://www.melexis.com/Assets/MLX90121_Cookbook_5100.aspx

Warning it is a 1MByte download. I also posted the schematic on abse.

The booster is on page 5.

I would like to know how to calculate the power gain and why it is
dependant on the voltage at the top of L3?

Any help on how this works would be appreciated.

Thanks,

IanM

M1 is operating as a switch i.e. in class C.

The output matching network presents a load R (150 ohms) to the drain.

The power drawn by this load is roughly V^2 / 2R where V is the supply
voltage at the top of L3.

 

[IanM]

"Andrew Holme" <ah@nospam.co.uk> wrote in message
news:rq0fl.11675$R71.8629@newsfe27.ams2...

"IanM" <nobody@no_where.co.uk> wrote in message
news:01407bea$0$22571$c3e8da3@news.astraweb.com...
Hi,

I have been working on an RFID project that uses a power booster from
a
Melexis cookbook.

http://www.melexis.com/Assets/MLX90121_Cookbook_5100.aspx

Warning it is a 1MByte download. I also posted the schematic on abse.

The booster is on page 5.

I would like to know how to calculate the power gain and why it is
dependant on the voltage at the top of L3?

Any help on how this works would be appreciated.

Thanks,

IanM



M1 is operating as a switch i.e. in class C.

The output matching network presents a load R (150 ohms) to the drain.

The power drawn by this load is roughly V^2 / 2R where V is the supply
voltage at the top of L3.

Thanks Andrew