PA required for -10dBm o/p power

[analog_ambi]

I am designing a transmitter with o/p power of -10dBm. This translates to a peak to peak voltage 200mV. Is there any necessity of power amplifier if the O/P is available from a LC oscillator capable of generating such Vpp=200mV

 

[godfreyl]

It's not necessary, but is useful.

If you make a simple transmitter with the oscillator directly connected to the antenna, you will find that the frequency changes a bit if you move the antenna or even just move your hand near it.

That's because the antenna affects the tuning of the oscillator. Adding an amplifier in between decouples the oscillator from the effects of the antenna and helps keep the tuning more stable.

There's lot's of good info about transmitters, antennas etc here on Harry Lythall's website.

 

[rohitkhanna]

I am designing a transmitter with o/p power of -10dBm. This translates to a peak to peak voltage 200mV. Is there any necessity of power amplifier if the O/P is available from a LC oscillator capable of generating such Vpp=200mV

The -10dBm translation to 200mV pk-pk is valid only for a load of 50ohm. Is your oscillator output developing this voltage across a 50 ohm load ?
If yes, then you are all set. As long as you make sure that your SWR stays close to 1 when you feed the signal to your antenna.

 

[analog_ambi]

Thank you godfreyl and rohit!