HMC346ALC3B application

1. When you wired an external op-amp with HMC346A as indicated in the datasheet, you only need to vary the voltage of V1 (from 0V to -5V). V2 will be complimentarily changed by the op-amp and I maintains the impedance match while attenuation is varied. Is this what you have been doing so far and still observe a sudden change of attenuation?

2. Since you have the HMC346A eval board, you can also check if the part is still functioning by not using the external op-amp first. You can find two power supplies and control V1 and V2 separately. Please refer to the figure "Relative Attenuation vs. Control Voltage @ 10 GHz" in the datasheet. You can try to check several combination points of V1 and V2, and to see if you can achieve the expected attenuation levels.

1. When you wired an external op-amp with HMC346A as indicated in the datasheet, you only need to vary the voltage of V1 (from 0V to -5V). V2 will be complimentarily changed by the op-amp and I maintains the impedance match while attenuation is varied. Is this what you have been doing so far and still observe a sudden change of attenuation?

2. Since you have the HMC346A eval board, you can also check if the part is still functioning by not using the external op-amp first. You can find two power supplies and control V1 and V2 separately. Please refer to the figure "Relative Attenuation vs. Control Voltage @ 10 GHz" in the datasheet. You can try to check several combination points of V1 and V2, and to see if you can achieve the expected attenuation levels.

If i want to control the v1 and v2 using external voltage, What is the relation between V1, V2 and I? Do i need to measure this on my own?