IQ mixer testing conversion gain

Hi,

I have a IQ mixer of gain = 12 dB (at frequency which I need). His LO power = +6 dBm, RF power = +2 dBm max. the power level at mixer output should be
+14 dBm as per data sheet.but instead of gatting gain,i got loss of power -10 dBm.the Ic is HMC1113LP5E

So I am asking for some help to find that ?

Thank you

Look at the first page of the data sheet, Electrical specifications line 6, 1dB compression poinit -7dBm input.
The plots indicate that the best you might get is a 1db compression point of -4dBm
I can't find any mention in the data sheet of RF input at +2dBm, the absolute maximum is +8dBm

The datasheet says input 1dB compression point = -7 dBm. You are feeding the mixer with + 2dBm and still expect specified performance?

sorry..that was wrong number.
I have given the RF input power of -20 dBm and LO power of +7 dBm.Im getting the IF power -30 dBm.its geeting loss not gain.

asgant said:

sorry..that was wrong number.
I have given the RF input power of -20 dBm and LO power of +7 dBm.Im getting the IF power -30 dBm.its geeting loss not gain.

Click to expand...

It's hard to say without seeing your set-up and the components which you used.You should give us more information including supply voltages and consumed current etc.

it is an IQ mixer. How you measure it is important. Are you using it as an image reject mixer (requires an external hybrid combiner), or as two independent I and Q outputs? What is your circuit? Is it your own PC board, or are you using a Hittite eval board?

These type of leadless chip carriers are pretty easy to screw up as you are assembling them. So i would first suspect a bad solder joint on one of the pads. Either an input, LO, or one of the bias voltages are ones to check. Also are you GROUNDING the center slug on the back of the pacakage (you should be able to see evidence of the solder flowing into the grounding holes on the backside of the board)?

if you are using your own PC board (i.e. not an eval board assembled by Hittite), it is likely one or more of the pads are not making contact properlyto the traces. Take an ohmmeter with some shrp pointy probes, and buzz out each connection from the board trace to that tiny side metal ofeach pad. Is there a connection on each? Are any of the signals accidentally shorted to ground? I really hate these leadless chip carriers!

hii biff44,
it is our own PC boards and we are using it as independant I andQ outputs.I have checked the entire board,supply voltage,grounding and the connections everything is perfect.
the application circuit given in the datasheet is what we are using.
still strugging for the output.

If the RF input is 9dB higher than the recommended -7dBm (P1dB) and you get only -10dBm at the output, could be because the RF input is already damaged.
According to the datasheet, AND if the RF input is not damaged, you should get a compressed output power of: -7dBm + 12dB = +5dBm

This is a 10-12GHz mixer, and at those frequencies you can lose many dBs due to poor layout design or a bad coax cable connection.

the absolute maximum input powers are:
RF Input +8 dBm, LO +10 dBm. Voltages +4.5 volts. IF you exceeded those in initial testing you very well could have blown out the chip.

IS it taking 160 mA approximately from the DC power supply,as it should be?

Time to reflow a new chip on there and see if it starts to work.

Also you could post the layout artwork you are using for both sides of the board, and we can see if there is something obviously wrong

Also: "pins 2, 4, 10, 12, 17, 19, 21 These pins and the exposed ground paddle must be connected to RF/DC ground"

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another idea: look at the IF output to make sure the chip is not oscillating due to poor layout.

hii..
yeah i changed the IC and now its working.the IC got damaged but my doubt is IC is taking current and voltage as per datasheet.the IF frequency is correct.except gain everything is working .if IC is damaged then nothing should be worked.In my case except gain everthing is working.

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thanku all for the help..

asgant said:

if IC is damaged then nothing should be worked

Click to expand...

This might be reasonable if it was damaged by reversing the power supplies or something similar, but if you just overload one input or output you may very well see partial functionality.