Broadband highly efficient linear millimeter-wave medium-power power amplifier design

5G (fifth-generation) mobile network’s FR2 band (i.e., 24.25 to 52.6 GHz) is currently used to support eMBB (enhanced Mobile Broadband) applications to achieve 10+ Gb/s download peak speed, and sub-1mS latency for the UR/LL, mMTC (ultra-reliable machine type communication) applications. The RF (radio-frequency) power amplifiers (PAs) are usually the most power-hungry components in the RF front-end modules (FEM) of a handset or in other portable wireless electronic products. Since the 5G FR2 band is considerably higher in frequency compared to the sub-6 GHz 5G FR1 band, the power-added efficiency (PAE), bandwidth (BW), and linearity of the mm-Wave 5G PAs will all be considerably lower than their 4G and sub-6GHz 5G counterparts, which makes the highly-efficient broadband and linear mm-Wave PAs design a critical area for the success of mm-Wave 5G. For example, path loss is higher at these mm-Wave frequencies so it would be necessary to use a larger number of more complicated mm-Wave phased array channels with MIMO (multiple-input and multiple-output) antennas to achieve 3-D beamsteering capabilities with the desired output power, which means inefficient PAs may create intolerable heat and reliability issues for mm-Wave systems. In mm-Wave 5G user equipment (UE) and femto/picocells, due to the increased number of channels, each PA’s output power (POUT) requirement will mostly only need to be in the sub-Watt range (i.e., <30 dBm), which is significantly reduced from their 4G/sub-6 GHz 5G counterparts. Also, if a PA can cover the entire ~20 GHz BW of the key mm-Wave 5G bands, it would be really attractive as it can greatly reduce the total number of FEMs needed for arrays, and is thus one key motivation for our broadband PAs design. Thus, in this proposed work we will investigate the design of mm-Wave PAs in the medium power range of ~ < 20 dBm, with very broad BW of ~ 20GHz, excellent broadband peak PAE > ~20%, and also good linearity. Thus this work looks at the design of broadband mm-Wave PAs in several state-of-the-art technologies for broadband commercial and DoD applications.

Embargo status: Restricted until 06/2172. To request the author grant access, click on the PDF link to the left.