The 5G_GaN2 project is covering activities from epitaxial material growth for development of GaN microwave technology up to the test of demonstrators in system environment.
In the first year the architecture and preliminary specification of the demonstrators for 5G base-station, SatCom and E-Band telecom Point to Point applications have been defined.
In parallel, the activity concerning the development of semiconductors GaN Technology and Wafer Level Packaging (WLP) technology has been launched: GaN wafers based on epitaxial material defined in the frame of the project are under manufacturing and the manufacturing flow of the WLP technology has been defined.
GaN/SiC transistors have been characterized and electrical models for the design of power amplifier up to 35GHz are available.
The GaN technologies are developed in parallel to the design of the first circuits.
An E-Band GaN HPA have been designed targeting telecommunication applications.
For SatCom application, amplifiers at 20 and 30GHz on GaN technology are designed.
A dedicated project site is available. The work performed in the frame of 5G_GaN2 has been presented in different international conferences and workshops.
During the second year of the project the first demonstrator packaged in FOWLP (transmitter/receiver 28GHz for 5G base station) has been manufactured. It was a preliminary run with available dies (GaN & GaAs) to experiment the FOWLP flow and adjust the parameters and design rules for the second demonstrator. The first hardware is under exploitation (physical analysis and electrical test).
The second demonstrator (transmitter/receiver 28GHz 5G BTS) with new MMICs (GaN and GaAs) is in progress. MMICs have been successully RF tested on-wafer and the FOWLP manufacturing is to be started.
A third demonstrator for 5G at 39GHz has been designed on advanced GaN technology. The MMIC is a fully integrated front end chip which includes HPA, driver, switch and LNA. The chip will be packaged in FOWLP. MMIC manufacturing is to be started.
For SATCOM applications, the amplifiers 20 and 30GHz on GaN technology have been manufactured and successfully on wafer RF tested. The MMICs are at assembly step in SMD plastic package (QFN).
In the 3rd year of the project, activities on GaN/Si and GaN/SiC technologies have been pursued at UMS, IAF, III-V Lab and CEA Leti with support of XFAB (GaN/Si). Deep analyses to assess the reliability and the robustness of the GaN FE technologies have been carried by University of Padova regarding buffer variant, channel thickness, back-barrier profile, epi-wafer variants. Significant progress on FOWLP packaging have been made. The demo 1 samples have been tested with good results on microstip line losses and pre-matched transistors. However, first MMICs of Demo 1 presented some defects (warpage) and open circuits preventing from RF and DC measurements. A new run using the new design 28GHz (Demo 2) is now completed at LETI (FOWLP process). New campaign of tests has been performed on this demo 2 by UMS and Benetel.
Regarding design activities, the run 1 of MMIC designs including tests in SMD plastic package is completed. Results of MMIC SATCOM at 30GHz and 20GHz are fully satisfying and in line with expectations. The second run of SATCOM MMICs is designed with improvements in terms of isolation, die coating and size. Manufacturing of the MMICs is completed and tested on-wafer. The second run of SATCOM circuits have been packaged in SMD plastic package and tested.
For the 5G applications at 39GHz (HPFE) and E-band (HPA), MMICs have been manufactured and tested successfully. The packaging using FOWLP process of LETI is completed on these 2 MMICs. HPFE 39GHz has been tested by UMS.
To compare GaN and commercial Si technology capabilities at 39GHz, a LNA and a switch have been designed on the 45nmRFSOI foundry (GF). Fabrication of these circuits is completed and on-wafer tests have been performed.
In 2021, 5GGAN2 partners have participated to virtual conferences (ISM2021, CS Mantech, ECTC2021). A publication in IEEE Microwave and wireless compound related to the HPA high efficiency has been issued by EAB.
In 2022, a full day workshop on technology/material and applications has been organised in the EUMW2021 international conference held in London in April 2022. 12 presentations from the 5GGAN2 partners has been presented for this workshop. A presentation about MMIC and integration technologies has been made during the last IMS2022 workshop in US, Denver. At EUMW2022 October 2022 in Milan UMS will present a paper entitled: "Packaged Ka-band GaN-HEMT High Power Transmit Module for Sat-Com applications".
