MMG20241HT1 - how i can make schema for impulse modulation?

[aviabarsik]

MMG20241HT1 - how i can make schema for impulse modulation control?

Ti=0.5mks

Thanks!

[LPP]

Not sure, what do you mean as "impulse" modulation.

MMG20241HT1 is an amplifier designed for 450–3800 MHz frequency range. It provides internal DC coupling capacitor at the input and thus it is not suitable to amplify video pulse signals.

If your aim is to amplify RF pulse (MCW modulated continuous wave signal) then the RF modulation should be provided by the source of RF signal. MMG20241HT1 itself doesn't provide any means to control the amplification.

To make MCW signal you can turn on/off RF signal from oscillator using SA630 SPDT switch. It can be used up to 1GHz.
https://www.nxp.com/docs/en/data-sheet/SA630.pdf

For amplitude/phase modulation you can use various RF mixers.
https://www.nxp.com/products/rf/rf-mixers/low-power-fm-if-systems:MC_1410862639730

Also, you can build RF switch using discrete components like PIN diodes or transistors.
https://ieee.li/pdf/essay/pin_diode_handbook.pdf

Have a great day,
Pavel

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[aviabarsik]

I need Pulse-Position Modulation (PPM)

Freq = 1100Mhz

impulse length = 0.5mks

i think using SA630 (after OSC, before MMG20241HT1)

it is good ?

[LPP]

SA630 frequency range is up to 1GHz. It is not as good at F>1GHz. Please, see datasheet Figures 6 and 9. Insertion loss and isolation at 1100MHz are about -3dB and -15dB respectively. So, you would have 12dB difference between ON and OFF states.

My suggestion is to use a third party device with better parameters at this frequency like AMD ADRF5020:
http://www.analog.com/media/en/technical-documentation/data-sheets/ADRF5020.pdf
http://www.analog.com/en/products/rf-microwave/rf-switches.html

Have a great day,
Pavel

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[aviabarsik]

thank you for advice!

ADRF5020 95$ vs ADG901 7$ 

whats the difference ? )

[LPP]

Using single pin diode in series configuration is a cost effective solution.

If using BAP55LX as SPST switch, If=1ma: ISL=15dB, IL=0.2dB, about 15dB difference between ON/OFF states. The result is similar to SA360 if being used at 1.575GHz

For a narrow band application like GPS, there is a simple way to improve isolation of the switch. Place inductor in parallel to the pin diode to resonate with the diode capacitance at the target frequency. It will not worsen ON performance but will dramatically improve isolation in OFF state

My simulation shows that BAP55LX in parallel with 36nH Murata LQW15AN36NG00 inductor provides more than 35dB isolation in OFF state and it is quite enough for your application.

Pin diode BAP55LX costs 0.3$ + inductors 3x0.05$ + capacitors 2x0.05$ = 0.55$ solution.
Have a great day,
Pavel

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[aviabarsik]

Thank you very much for advice!

Can you give me schema with diode screen-capture from ADS ?