RF Filters

Image	Part Number	Description / PDF	Quantity	Rfq
	LFL182G50TC1B905 TOKO / Murata	RF FILTER SIGNAL CONDITION 0603	0
	LFL215G51TC1A149 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL211G44TC1A014 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL182G45TC1A202 TOKO / Murata	RF FILTER LOW PASS 2.45GHZ 0603	0
	LFL211G90TC1A008 TOKO / Murata	RF FILTER LOW PASS 1.907GHZ 0805	0
	LFL21600MTC1A002 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL211G66TC1A053 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL211G79TC1A011 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL18924MTC1A052 TOKO / Murata	RF FILTER SIGNAL CONDITION 0603	0
	LFL21902MTC1A018 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL152G01TC1A271 TOKO / Murata	RF FILTER SIGNAL CONDITION 0402	0
	LFL181G81TC2A162 TOKO / Murata	RF FILTER SIGNAL CONDITION 0603	0
	LFL215G37TC1A210 TOKO / Murata	RF FILTER LOW PASS 5.375GHZ 0805	0
	LFL211G88TC1A020 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL215G25TC1A156 TOKO / Murata	SIGNAL CONDITIONING	0
	LFL21897MTC1A017 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	0
	LFL182G45TC1A108 TOKO / Murata	RF FILTER SIGNAL CONDITION 0603	0
	LFL15869MTC1B787 TOKO / Murata	RF FILTER LOW PASS 869.5MHZ 0402	0
	LFL18815MTC2A072 TOKO / Murata	RF FILTER SIGNAL CONDITION 0603	0
	LFL211G89TC1A015 TOKO / Murata	RF FILTER SIGNAL CONDITION 0805	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.