This is the second blog post in a 2-part series looking at small cell base
In the first part of our
series, we covered the basics of small cells and how they fit into the evolution of 4G and 5G.
In this final post in the series, we sat down with Tuan Nguyen, Qorvo's product line director for
our wireless infrastructure products, to get his insights on the latest design challenges and
trends in the small cell market.
What are some of the latest trends related to
- LTE for usage in unlicensed bands: Also known as LTE-U and Licensed Assisted
Access (LAA), unlicensed spectrum is starting to be implemented in small cell base stations. This
unlicensed band access overlays LTE over the Wi-Fi band and provides carriers with another
pipeline where they can control and guarantee quality of service (QoS).
- Increased number of bands per system: A couple of years ago, a lot of small
cell base stations were just for single band. Many are now dual band, and moving forward in the
next year or two, customers are developing and implementing triple-band systems. This will
increase the system-level requirements for small cell solutions, both in terms of the number of
components required and the complexity of the overall system design.
- Customers designing with more efficient systems: Systems targeted for
shipment later this year are implementing linearization, which requires power
amplifiers that are much more efficient than they are today. Today, systems are designed where
the power amplifiers typically operate in backed-off mode, which means that the system just
works without worrying how the PA performs. Linearization uses feedback so that the signal gets
"cleaned up" by the baseband chipset and allows PAs to operate with much higher efficiency,
translating into lower power consumption for the system.
- Continued growth: The small cell market has been emerging for a while, but
over the past two years we have seen significant growth, at 50% year over year. Multiple
analysts such as IHS Technology and Mobile Experts expect that small cell deployments will
total more than 1 million small cell base stations for 2017.
Learn more about the latest trends in small cells:
What are common or new challenges customers
have when designing for small cell applications?
- Increasing number of bands per system: Customers historically are designing
these small cell systems for MIMO applications (multiple input/multiple output), which typically
have 2 transmitters and 2 receivers per frequency band. As base stations incorporate multiple
channels, it means more components — for instance, a three-band system would need six
separate PAs (2 transmitters x 3 bands = 6 PAs) — which adds complexity, size and power
consumption. Customers need the systems to be easy to design, easy to use (i.e., internally
matched components), and efficient.
- Ensuring good isolation and band separation for the transmit/receive
channels, specifically for Band 3 (1.8 GHz). The band separation is only 20 MHz, which
requires very high isolation out of the duplexer.
How does Qorvo help our customers solve these
Over the last two years, we've significantly expanded our portfolio of small cell filters and
PAs, targeting products for specific frequency bands. Our customers have seen some of the following key benefits:
Filters for small cells: Qorvo's BAW technology delivers high
isolation and performance, particularly in our duplexers. Our small cell duplexers provide
very good passive intermodulation (PIM) by reducing nonlinearities that may be introduced in the
duplexer — which our customers have said is very important.
- Small cell power amplifiers: Qorvo PAs are internally matched and designed
to provide temperature compensation inside the circuitry. This means our PAs are effectively
plug and play and easy to use, which allows customers to easily design their system.
Qorvo Articles on Small Cells
Read what Qorvo experts have to say:
Qorvo has a complete
small cell portfolio and is the only supplier to provide the entire RF front end, including low
noise amplifiers (LNAs), PAs, filters/duplexers and switches. All of our small cell products
- High linearity
- High isolation
- Low power consumption
- Low link budget
Visit our Small Cells
application page for all our latest products supporting this market, as well as block diagrams for
our small cell FDD and TDD solutions.