Design Of L band to Ku Band Upconverter

jiripolivka said:

Suitable mixers for your upconverter are offered by MiniCircuits. Select LO power level for your linearity specifications and select your 12.8 GHz LO to fit.

As your LO. is fixed, then what you need for the "synthesizer"? If you need a stable PLO for the local oscillator driven by 10 MHz reference, you must find a PLO maker: try Luff Research for the best technology.

The RF output from the mixer will have to pass through a 13.75 to 14.5 GHz band-pass filter which will reject the lower "image" band. There are many companies making custom filters you can use.

For a complete specifications you must include the IF input power level and the P-1dB for the RF output which typically is ~7 dB lower than LO input power.

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BigBoss said:

**broken link removed**

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srlraghuls said:

Thank you for your Reply
My Input IF Frequency is 70 ± 4 MHz fixed with power level of 0 dBm nominal .First I need to Up Convert the 70MHz IF signal to 950MHz to 1700Mhz(L Band IF), Then the L Band is to be Upconverted to 13.75GHz to 14.5GHz(Ku Band) using a fixed LO. The Output Power Level is 0 ± 3dBm at 13.75GHz to 14.5GHz

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Thank you for your Reply

The Data Sheet For the VCO is Not Available.for TFF11126HN/N1 the Input signal frequency is 48.3 MHz to 808.8 MHz but my Referency oscillator Frequency is 10MHz and If i use Frequency Multiplier then my phase noise degrades.

My Input IF Frequency is 70 ± 4 MHz fixed with power level of 0 dBm nominal .First I need to Up Convert the 70MHz IF signal to 950MHz to 1700Mhz(L Band IF), Then the L Band is to be Upconverted to 13.75GHz to 14.5GHz(Ku Band) using a fixed LO. The Output Power Level is 0 ± 3dBm at 13.75GHz to 14.5GHz

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jiripolivka said:

All right, so you need two upconverters. With 0 dBm input at 70 MHz you need first a +10 dBm LO in put to get to 0.95-1.7 GHz, and a synthesizer LO to position your 70 MHz spectrum (bandwidth to define) to the first IF. MIxers again from Mini Circuits, for a synthesizer ask Luff Research. You need to define serial or parallel tuning and reference source (can be included in the LO synthesizer).
The second stage upconverter I have discussed earlier. Filters will be needed and you must define their pass as well as reject band and rejection loss. Custom filters are best, ask Lark or K&L.

To get 0 dBm at final output you need >+7 dBm LO to mixer and certainly an IF as well as RF amplifier. Again check MiniCircuits.
As your reference is 10 MHz, choose the best one. You must use multiplication and phase noise must degrade. Good phase-locked oscillators help to get a good PN.

As you are going into this design for a first time, find an existing commerciAl model of this upconverter (used in all old VSATs) and learn from the design as well as its parameters. Filtering can be quite difficult and as can see you have no idea about them.

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