5G Pioneer Band FEM
The Design of a Multi-Chip SMT Front-End Module
for the 26 GHz 5G Pioneer Band
By by Graham Pearson*, Liam Devlin* and Mike GeenƗ *Plextek RFI Ltd, ƗFiltronic Broadband Ltd
5G communications systems will offer
huge increases in data rates and
aim to provide a service with seemingly
infinite capacity. This will be facilitated
by the use of mm-wave frequencies,
where large bands of contiguous spectrum
can be made available. Although the
mm-wave bands for 5G have yet to be
confirmed, development work is already
under way in several of the candidate
bands, including the band around 26 GHz
band that has been identified by the EU’s
Radio Spectrum Policy Group (RSPG) as
the ‘Pioneer Band’ for 5G in Europe.
FREQUENCY BANDS
The agreement of the mm-wave bands
for 5G will be finalised at the World Radio
Conference in 2019 (WRC-19). The
candidate bands 1 where development
work is already taking place include the
FCC licensed bands at 28 GHz (27.5
– 28.35 GHz), 37 GHz (37 – 38.6 GHz)
and 39 GHz (38.6 – 40 GHz) and the
26 GHz European pioneer band (24.25
to 27.5 GHz).
The RSPG recommended the 26 GHz
band as the pioneer band for mm-wave
5G in its Strategic Roadmap Towards
Europe, published in November 2016
2. Those attempting to develop mmwave
equipment covering the 24.25 to
27.5 GHz band have discovered that
component availability is somewhat
limited.
This article describes the design, implementation
and measured performance
of an SMT packaged multi-chip front-end
component intended to address this limitation.
It comprises a low-noise amplifier
(LNA), power amplifier (PA) and transmit/
receive switch housed in a custom
laminate surface mount (SMT) package
measuring 10-mm x 10-mm. Low loss RF
filtering has also been integrated into the
package structure.
DESIGN AND IMPLEMENTATION
A single SMT component has been
developed, which includes the mm-wave
blocks of a Front-End Module (FEM) to
cover the full 26 GHz 5G band (24.25 to
27.5 GHz). A block diagram depicting
the functionality of the FEM is shown in
Figure 1. It includes three GaAs MMICs
Figure 1: Block diagram of the 26 GHz FEM.
Figure 2: Photograph of the 26 GHz FEM prior to lidding.
Figure 3: Photograph of the evaluation PCB with SMT FEM solder attached.
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