• VCO hmc778替代产品

    我们主要做分布式光电传感设备,之前用的VCO评估板型号为HMC778。想咨询使用这个产品来提供10.8G的电信号,参考输入0-350MHZ起到什么作用?

    HMC778被标注为新设计不推荐使用本产品,在同类型推荐中HMC512评估板,为什么没有参考输入和USB接口板来连接电脑?以及其HMC512的VTUNE接口如何连接电源?

    最后想问一下ADF5356评估板是否完美替代HMC778并适用我们的工作?

    谢谢大家,期待大家的回复。

  • HMC778 RFOUT coupling cap (why 100 pF)?

    Hello ADI,

    Why was a 100 pF coupling cap used on the HMC778 RFOUT on the eval board schematic?  Since this part operates around 10 GHz I would have expected that a much smaller coupling cap would be used.  I swept a 100 pF, C0G 0402 cap at 10 GHz and the…

  • HMC778

    Hi All 

    Is it possible to improve the Phase Noise of the HMC778. (9.6 - 10.8 GHz)

    The current configuration is -106/-102 dBc/Hz @ 10 kHz. I'm looking for at least for a Phase Noise of -110 dBc/Hz.

    If not, Is there maybe an alternative device i can…

  • HMC778:Output signal performed bad

    Hi! I had some problems when using HMC778. Now i think i have set right values to configure HMC778, and the ouput signal seemed to be locked. But the quality was very bad and i will attach a spectrum picture of it. I have no idea what can cause this issue…

  • HMC778 How to mute output signal and force LD low?

    HMC778 after powerup (without registers programming) working on maximum VCO Output Frequency (about 10.9 GHz) and LD is unstable: sometimes LD=1 or LD=0, or fastly switching between 1 and 0.

    How to disable output and force LD=0 (in other words: how to…

  • HMC778 RF output power too low

    Refer to HMC778 evaluation board, I have made a PLL board and its schematic is shown below. The RF output power of hmc778 should be 9dbm@10GHz. And I want to get 9-5+14=18dbm output power through a attenuation network and PA hmc441.

    The problem is the…

  • About HMC778 PIN: VCCVCO

    Hi,

    I have noticed that in the schematic of evolution board of HMC778, there is an option for pin "VCCVCO2". Shown as following.

    I want to ask the function of "JP2" or is there any difference if I provided 5V to VCCVCO2 or not?…

  • HMC778 Evaluation Board some time the output power drops to -9dbm

    Hello,

    We are using the HMC778 Evaluation board.  we have observed that some time we get  +9dbm output from the synthesizer board.  But many time we have seen that it drops to -9dbm.

    Then we reset the synthesizer board  many times and again some time the…

  • HMC778 SPI Programming

    Dear Sir,

    I am using HMC778 to generate single frequency output at 10.8 GHz. I am using SPI in HMC mode to program the device and the base XTAL frequency to HMC778 is 100 MHz. Can I get the register sequence and value for this configuration ?? 

    Than…

  • HMC778 Integer Mode Freq Tuning Equation

    As shown in Functional Diagram VCO Freq always divided by 2 and then optionally can be divided by 2 again. Then equation 5 is not correct. There is no addition "divide by 2". Am i right?

    The main question is i am trying to setup HMC778 in integer…