About ACP & PAE of HMC8500 for LTE

Hello,

We do not have load-pull data for this part. With respect to the possibility of alternate matching to improve ACP, I will ask a designer for comment and reply soon.

Regards,

SMcBride

Noted. Due to project kicks off in rush, please help to update as soon. 

Thanks

Hi,

Are you working with the HMC8500LP5DE or the HMC8500PM5E? In case you are not aware, the LP5DE version has Last Time Buy status, while the PM5E version is the one that is Recommended for New Designs. For that reason we recommend you work with the PM5E, rather than the LP5DE. At this point I'll assume you're working with the PM5E.

Below I summarize what the designer told me:

• The third order IMD components are what tends to generate spectral regrowth in the adjacent channel
• For that reason he thinks the ACPR can be improved by reducing the IMD3 components i.e., improving the OIP3
• While you may in general be able to match for better OIP3, it's difficult to say how much improvement could be obtained and it all depends upon how far you currently are from the optimum impedance
• With the HMC8500 we did not investigate adjusting the match to optimize OIP3 and/or ACPR
• Customers can try to optimize the match for OIP3, but they would need to be careful about stability

From what I remember, during product development our matching activities were mainly focused on optimizing to get the best trade-off of Power, Gain, and PAE across the entire operating frequency range...not just within a narrow range such as your 1.3-1.5 GHz.

Because our group does not currently have the capacity to try such optimization, I asked the designer if he thinks it's possible to improve the match such that your ACP target of 40 dBc can be met at Pout=+30 dBm LTE (+35 dBm CW) in the 1.3-1.5 GHz range. He said that, if the measurement results you provided are indeed correct then, optimizing the matching would likely not allow an ACP improvement of 10 dB.

I will see if we have another part that might be expected to meet the requirement.

Regards,

SMcBride

Hi,

Are you working with the HMC8500LP5DE or the HMC8500PM5E? In case you are not aware, the LP5DE version has Last Time Buy status, while the PM5E version is the one that is Recommended for New Designs. For that reason we recommend you work with the PM5E, rather than the LP5DE. At this point I'll assume you're working with the PM5E.

Below I summarize what the designer told me:

• The third order IMD components are what tends to generate spectral regrowth in the adjacent channel
• For that reason he thinks the ACPR can be improved by reducing the IMD3 components i.e., improving the OIP3
• While you may in general be able to match for better OIP3, it's difficult to say how much improvement could be obtained and it all depends upon how far you currently are from the optimum impedance
• With the HMC8500 we did not investigate adjusting the match to optimize OIP3 and/or ACPR
• Customers can try to optimize the match for OIP3, but they would need to be careful about stability

From what I remember, during product development our matching activities were mainly focused on optimizing to get the best trade-off of Power, Gain, and PAE across the entire operating frequency range...not just within a narrow range such as your 1.3-1.5 GHz.

Because our group does not currently have the capacity to try such optimization, I asked the designer if he thinks it's possible to improve the match such that your ACP target of 40 dBc can be met at Pout=+30 dBm LTE (+35 dBm CW) in the 1.3-1.5 GHz range. He said that, if the measurement results you provided are indeed correct then, optimizing the matching would likely not allow an ACP improvement of 10 dB.

I will see if we have another part that might be expected to meet the requirement.

Regards,

SMcBride

It's right for PM5E currently. So, please help to clarify if possible to improve ACP about 10dB by matching optimizing or other recommend one to meet the spec ?  Thanks.

Hi Kenton,

Sorry for the delay, our EZ alerts are not working correctly.

The HMC8500 designer believes that 10 dB of ACP improvement would not be possible by match optimization (regardless of whether you're using the PM5E or the LP5DE).

At your frequencies the HMC8500 currently has the highest OIP3 of any part from our product line so, we unfortunately do not have another ADI part to recommend that will meet your ACP specification.

Regards,

SMcBride