upconverter

oh, please tell more detail, like what is your hard-software system

i want to design an upconverter for upconvert a signal from baseband to uhf (400 to 870 Mhz).

Please do specify in detail the technology you want to realize your up-converter such as CMOS of BiCMOS, judging from your frequency of application, it could be said that CMOS technology would play the trick, in realizing the upconverter. First get hold some basics of four quadrant multipliers, phase shifters and active BPF's in CMOS technology, then build up a balanced modulator to perform your up conversion action.

Rgds

Dear hrkhari;
thanks
it's not important the technology for me in this step.
i want to know that about the ICs that made for this purpose.
for example is there any IC for synthesizer for UHF band (400-870mhz)?
and i want to know about specification of upconverter?

Hi,

The specs are decided by the application. If its a commercial design, then the end user has to have an idea of what is required. otherwise if its a hobby design, you can yourself specify the common parameters. The basic parameter may look like -
1. Input and output frequencies
2. Input and output power levels
3. Input and output VSWR
4. Input and output Impedances
5. Gain flatness and stability
6. Third order intercept point
7. AM/PM conversion
8. Group delay etc.

dear vagarwal;
how about group delay? what is its standard for output of upconverter?
is +/-15 ns good for output?

dear vagarwal;
is vswr important in this step when output power is around 30dBm?

Dear m229,
your output frequency band is in the IV and V TV UHF band. Are you trying to build up TV upconverter (TV IF or I band to UHF)? Designs differ regarding to type of modulation of the signal you are trying to convert. It is not the same thing if you want to convert analogue TV signal or digital or maybe something else.

Have you considered to buy a very cheaper TV modulator rather than design it?
On the broadcast TV market there are small, cheaper, and well engenerized modules.

Dear Borber;
this upconversion is for digital tv signal and from baseband/IF to uhf band.
my standard for dtv is the dvb-t standard.

you can find some example in ADS!

dear m229,

I suppose 30 dBm is sufficiently high a power to consider designing for good input and output return losses, atleast better then 12-15 dB.

And group delay of around 15 ns is OK.

regards.

dear vagarwal;
is the meaning of u'r 15 ns is : peak to peak of gd figure is 15 ns or 30 ns.
thanks