RF Filters

Image	Part Number	Description / PDF	Quantity	Rfq
	0915LP15A026E Johanson Technology	RF FILTER LOW PASS 915MHZ 0805	0
	5487BP15B675E Johanson Technology	RF FILTER BAND PASS 5.5GHZ 0805	0
	2450BP18C100DE Johanson Technology	RF FILTER BAND PASS 2.45GHZ 1206	0
	1810LP07B200T Johanson Technology	RF FILTER LOW PASS 1.81GHZ 0402	0
	5487BP15C675E Johanson Technology	RF FILTER BAND PASS 5.5GHZ 0805	0
	2450BP39C100DE Johanson Technology	RF FILTER BAND PASS 2.45GHZ 1008	0
	2450BP41D100A Johanson Technology	RF FILTER BAND PASS 2.45GHZ 1210	0
	2450BP18C100BE Johanson Technology	RF FILTER BAND PASS 2.45GHZ 1206	0
	0898LP18A035E Johanson Technology	RF FILTER LOW PASS 897.5MHZ 1206	0
	2442LP18A083E Johanson Technology	RF FILTER LOW PASS 2.4GHZ 1206	0
	5487BP15B675 Johanson Technology	RF FILTR BANDPASS 5.4875GHZ 0805	0
	2450BP41D100BE Johanson Technology	RF FILTER BAND PASS 2.45GHZ 1210	0
	5487BP15C675 Johanson Technology	RF FILTR BANDPASS 5.4875GHZ 0805	0
	0869LD14A1810T Johanson Technology	RF FILTER LO PASS DL 850/1800MHZ	0
	1810LP07C0200T Johanson Technology	RF FILTER BP ULT LO PROF 2.45GHZ	0
	6120BP39A0240E Johanson Technology	RF FILTER BAND PASS 6.12GHZ 1008	0
	2450BP15M0100E Johanson Technology	RF FILTER 2.45GHZ 0805	0
	2400LP18A0200E Johanson Technology	RF FILTER LOW PASS 2.4GHZ 1206	0
	1810BP07C200T Johanson Technology	RF FILTER BAND PASS 1.81GHZ 0402	0
	4560BP39A0180E Johanson Technology	RF FILTER BAND PASS 4.56GHZ 1008	0

RF Filters

1. Overview

RF Filters are passive components that selectively allow or block specific frequency ranges in radio frequency (RF) systems. They are critical for signal integrity in wireless communication by eliminating interference, enhancing signal clarity, and ensuring compliance with regulatory standards. Modern applications include 5G networks, Wi-Fi systems, radar, and IoT devices.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Bandpass Filter	Allows frequencies within a specific range	Cellular base stations, Wi-Fi routers
Low-pass Filter	Passes frequencies below cutoff frequency	Power amplifiers, GPS systems
High-pass Filter	Attenuates frequencies below cutoff frequency	Satellite communication systems
Band-reject Filter	Blocks specific frequency bands	Medical imaging equipment
SAW Filter	Uses surface acoustic waves for precise filtering	Smartphones, automotive radar
BAW Filter	Employs bulk acoustic resonators for high-frequency operation	5G mmWave devices, WLAN modules
Cavity Filter	Metallic resonant cavities for high Q-factor	Radio astronomy, military communication

3. Structure and Components

Typical RF filter structures include:

Resonant Elements: Determine passband frequencies (e.g., quartz crystals in SAW filters)
Transmission Lines: Microstrip or coplanar waveguides for signal propagation
Dielectric Materials: Substrates like alumina or LTCC for impedance control
Enclosure: Metal housing for EMI shielding (cavity filters) or surface-mount packages
Ports: Input/output connectors (SMA, N-type) or PCB pads

Advanced designs integrate MEMS tuning mechanisms or LTCC multilayer structures for miniaturization.

4. Key Technical Specifications

Parameter	Description	Importance
Frequency Range	Operational bandwidth (e.g., 2.4-2.5 GHz)	Determines application compatibility
Insertion Loss	Signal attenuation in passband (e.g., <1.5 dB)	Impacts system sensitivity
Bandwidth (3dB)	Passband width at half-power points	Defines frequency selectivity
Rejection Ratio	Stopband attenuation level (e.g., >40 dB)	Interference suppression capability
Power Handling	Maximum input power (e.g., 20W CW)	Prevents component damage
Temperature Stability	Frequency drift vs temperature (e.g., 50 ppm/ C)	Ensures operational reliability

5. Application Fields

Telecommunications: 5G NR base stations, fiber optic networks
Aerospace: Avionics navigation systems, satellite transponders
Medical: MRI RF coils, ultrasound imaging equipment
Automotive: V2X communication modules, 77GHz radar systems
Industrial: Wireless sensor networks, RFID readers

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Murata Manufacturing	SAWLF5G30D	3.3-4.2 GHz BAW filter for 5G
Qorvo	QPM2515	2.3-2.7 GHz bandpass filter, 100W power rating
Skyworks Solutions	SKY13460	DC-6 GHz SPDT switch with integrated filters
Mini-Circuits	BFCN-1100+	Cavity filter with 1050-1300 MHz range
TE Connectivity	RFHF35-2.92M	High-frequency coaxial filter up to 40 GHz

7. Selection Guidelines

Key considerations:

Frequency Requirements: Match passband with system operating bands
Power Handling: Ensure ratings exceed maximum system power
Environmental Conditions: Temperature (-40 to +85 C), humidity resistance
Form Factor: SMD for compact designs vs. coaxial for high-power applications
Cost vs. Performance: Trade-off between ceramic filters (low-cost) and cavity filters (high-stability)

Case Study: Selecting a BAW filter for 5G mmWave devices requires <0.5 dB insertion loss, 28 GHz operation, and compliance with 3GPP TS 38.141-1 standards.

8. Industry Trends and Future Outlook

Key development trends:

Higher Frequency Operation: mmWave filters for 5G/6G (24-100 GHz) using photonic bandgap structures
Miniaturization: Wafer-level packaging reducing SAW filter size to 0.4x0.2 mm
Integrated Solutions: Filter+LNA modules for IoT devices (e.g., Qorvo's QM33013)
Advanced Materials: Lithium niobate on silicon (LiNoSi) substrates improving temperature stability
Software-Defined Radio: Tunable RF filters with MEMS or ferroelectric materials

The market is projected to grow at 9.8% CAGR (2023-2030), driven by automotive radar and satellite internet demand.