Hello, I prepared a eval board of my own with an external 3db-90* Coupler + HMC525 IQ Mixer.
Amplitude imbalance between arms of the coupler is 0.4db while phase imbalance is +- 4 degrees.
I gave LO with +15dbm power @4.3Ghz, and RF with -10dbm @2Mhz, same with values in datasheet except for IF=100 Mhz to IF = 2 MHz. I expected to see a single-sideband upconversion
with power difference of about 30db between 4.3Ghz + 2 Mhz and 4.3Ghz - 2 Mhz; however, they were about even power.
What may be the source of this error?