5G Technology World

  • 5G Technology and Engineering
  • Apps
  • Devices
  • IoT
  • RF
  • Radar
  • EE Learning Center
  • 5G Videos

Filters keep RF signals in line

By Martin Rowe | September 17, 2021

In a video interview with 5G Technology World, Resonant’s Mike Eddy explains how RF filters keep wanted signals in an interference out. It’s all in the physics.

As bandwidth gets crowded, governments auction more spectrum to accommodate our insatiable demand for data. While 3G used frequencies around 1 GHz, 4G expanded to around 2 GHz. 5G devices, however, operate at frequencies from 600 MHz to 900 MHz, from 3 GHz to 6 GHz, and mmWave frequencies starting at 24 GHz. Each frequency band in use today needs a filter to keep wanted RF energy in band while keeping unwanted RF energy out.

Given the size and power constraints of today’s 5G devices, using filters made from discrete components is out of the questions. Filters must be small, not only in terms of PCB footprint but in term of thickness. With so many frequency bands in use — and more coming, cell phones needs many filters. In the video, Mike Eddy, VP of Corporate Business Development and Marketing at Resonant explains that 5G phones can have over 100 filters to accommodate cannular frequencies. Why so many? Because we expect are phones to work anywhere in the world and frequencies vary across countries.

“There will be a move from IPD (integrated passive device) and low temperature co-fired ceramic (LTCC) filters,” said Eddy. “5G phones need acoustic wave filters for cellular, Wi-Fi, Bluetooth, UWB, and other wireless technologies.”

filters separate frequencies

Band-pass filters separate a composite signal into its frequency components. Click image to enlarge.

Eddy explains the physics behind filter technologies such as surface acoustic wave (SAW), temperature compensated surface acoustic wave (SAW), Temperature-compensated SAW (TC-SAW), BAW film bulk acoustic resonator (FBAR) and Resonant’s XBAR technology.

Eddy also explains why phones need so many filters because they need a filter for every frequency. The addition of MIMO in 5G phones multiplies the need for more filters because each antenna element needs its own filter for each operating frequency band.

Related articles

  • 5G RF filters need more innovation by Mike Eddy
  • RF/Microwave bandpass filter implementations, Part 1: Distributed filters</a>
  • Filters, Part 2: SAW and BAW devices for RF
  • 5 things you need to know about 5G filters

 

Comments

  1. Brenda Lord says

    November 4, 2021 at 12:47 pm

    Really interesting, fantastic explanation!

    Reply

Tell Us What You Think! Cancel reply

Related Articles Read More >

5G altimeter interference: aviation versus telecoms
BAW filter application
BAW filters keep RF interference out
ETSI launches intelligent surfaces effort
Marki Microwavediplexer
Marki adds four models to diplexer line

Special Issue: 5G Handbook

Need 5G Technology World news in a minute?

We Deliver!
5G Technology World Enewsletters get you caught up on all the mission critical news you need. Sign up today.
Enews Signup

EE World Online Twitter

Tweets by @RandDWorld

EE TRAINING CENTER CLASSROOMS

“ee

“ee

“ee

“ee

“ee

“ee
5G Technology World
  • Enews Signup
  • Contact Us
  • EE World Online
  • DesignFast
  • EDABoard Forums
  • Electro-Tech-Online Forums
  • Microcontroller Tips
  • Analogic Tips
  • Connector Tips
  • Engineer’s Garage
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • Wire & Cable Tips

Copyright © 2022 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search 5G Technology World

  • 5G Technology and Engineering
  • Apps
  • Devices
  • IoT
  • RF
  • Radar
  • EE Learning Center
  • 5G Videos