RF Filters

Image	Part Number	Description / PDF	Quantity
	LP0DA1950A700 Elco (AVX)	SIGNAL CONDITIONING 1950 MHZ SIZ	21
	5697CR45A0360E Johanson Technology	RF FILTER BAND PASS 5.67GHZ 5SMD	527
	LP0BA1220A700 Elco (AVX)	SIGNAL CONDITIONING 1220 MHZ SIZ	28
	DEA205425BT-2190E2 TDK Corporation	RF FILTER BANDPASS 5.435GHZ 0805	7990
	SNLP-1G Belden	LOW PASS FILTER TO 1 GHZ	0
	BP0EA4440A7TR Elco (AVX)	RF FILTR BANDPASS 4.44GHZ 30ULGA	0
	B144MB1S Knowles DLI	BANDPASS	32
	5400BP14A0950T Johanson Technology	RF FILTER BANDPASS 5.375GHZ 0603	0
	LP0AA2640A700 Elco (AVX)	SIGNAL CONDITIONING 2640 MHZ SIZ	0
	1905BP18A0050E Johanson Technology	RF FILTER BANDPASS 1.905GHZ 1206	0
$LP0805H2900ASTR\500$	LP0805H2900ASTR\500 Elco (AVX)	LOW PASS FILTER	0
	SNLP-1GCW Belden	LOWPASS FILTER 1GHZ,COMBO WAVE	0
$HF0AA2470A7TR\250$	HF0AA2470A7TR\250 Elco (AVX)	RF FILTER HI PASS 2.47GHZ 16ULGA	236
	LP0AA0156A700 Elco (AVX)	SIGNAL CONDITIONING 156 MHZ SIZE	35
$LP0AA4370A7TR\250$	LP0AA4370A7TR\250 Elco (AVX)	RF FILTER LO PASS 4.37GHZ 16ULGA	0
	LFL182G54TC1B838 TOKO / Murata	RF FILTER LOW PASS 2.54GHZ 0603	0
	LP0AA1610A700 Elco (AVX)	SIGNAL CONDITIONING 1610 MHZ SIZ	30
	1900HP41C0500E Johanson Technology	RF FILTER HIGH PASS 1.9GHZ 1210	0
	6960BP39A0280E Johanson Technology	RF FILTER BAND PASS 7GHZ SMD	0
	3350BP39A0500E Johanson Technology	RF FILTER BAND PASS 3.35GHZ 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.