Accute Micro Electronics Co. Ltd.
- Manufacturer of dielectric ceramic filters for the communications industry. Includes product specifications, online catalogue (PDF), and photographs of their facility.
- http://www.accutemicro.com/

LCR Electronics, Inc.
- Design, development and manufacturing of custom and standard EMI filters.
- http://www.lcr-inc.com/

Piezo Technology, Inc.
- A manufacturer of frequency control products such as crystal oscillators, crystal filters, lc filters, and crystal resonators.
- http://www.piezotech.com

Oceangrove Developments Limited
- Produce RFI suppression capacitors, chokes and filter systems.
- http://www.oceangrovedev.net

TTE
- Produces bandpass filter, rf filter, and high pass filters.
- http://www.tte.com

Netcom Inc.
- Manufactures custom lc filters, oscillators, phase locked loops, crystal filters, and power supplies.
- http://www.netcominc.com

AEF Solutions
- Filtered connector solutions for electro magnetic interference including lightning and transient suppression.
- http://www.aefsolutions.com/

KR Electronics
- Designs and manufactures precision filters from dc to 3 GHz.
- http://www.krfilters.com

K-COM
- Manufacture products for attenuation of radio frequency interference (RFI) used by amateur (ham), short wave and Citizen Band (CB) radio operators . Includes product specifications, technical documentation, and FAQs.
- http://www.k-comfilters.com/

Colby Instruments, Inc.
- Manufacturer of precision programmable delay lines and phase shifters. Both mechanical and electronic solutions are offered with resolutions down to 0.25 ps, and bandwidth from dc to 18 ghz (dc to 40 gb/s nrz).
- http://www.colby-inc.com/

Jiaxing Acoustic Electric Industrial Company
- Manufacturer of saw devices, including SAW filters, resonators and duplexers.
- http://www.sawseek.com/

Spectrum Control Inc.
- Manufactures aline of EMI/RFI filters, power products and EMC testing services including capacitors, discrete filters, filtered arrays, ferrite inductors, patch antenna elements and gaskets and shielding.
- http://www.spectrumcontrol.com

Pole Zero Corporation
- Manufactures digitally tuned RF filters, notch filters, preselectors and low noise amplifiers.
- http://www.polezero.com

ITF Co.,Ltd.
- Manufacturer of high-performance surface acoustic wave (SAW)components. Application areas include base stations, repeaters, terminals, HDTV and SAW resonators.
- http://www.itf.co.kr

Genisco Filter Corp.
- A custom solutions manufacturer for a variety of electromagnetic and radiofrequency interference problems.
- http://www.genisco.com

Arcotronics
- EMI EMC RFI filters and interference reduction engineering solutions.
- http://www.arcotronics.net

OKY R&D Co., Ltd.
- Manufacturer of EMI/EMC filters, choke coil and inverter surge filters.
- http://www.oky.co.kr/

Vortex Technologies, Inc.
- Supplier of isolators, control surge protectors, and EMI\RFI filters.
- http://www.vortextek.com/

Curtis Industries
- Full line manufacturer of RFI filters - general purpose, high performance switching power supply, medical UL544, 3 phase, power entry modules.
- http://curtisind.com

Murata Electronics North America
- Produces a.o. feedthrough and SAW filters.
- http://www.murata.com/

Communications & Energy Corporation
- Manufactures and sells microwave filters for wireless television, cable television, low-power television, and personal communications service.
- http://www.cefilter.com/

Custom Suppression, Inc.
- Custom manufacturer of miniature RFI filters and filtered connectors with suppression and transient devices.
- http://www.customsuppression.com