RF Filters

Image	Part Number	Description / PDF	Quantity
	LP0805A2750ASTR Elco (AVX)	LOW PASS FILTER	0
	LP0AA0185A700 Elco (AVX)	SIGNAL CONDITIONING 185 MHZ SIZE	35
	LP0DA1810A700 Elco (AVX)	SIGNAL CONDITIONING 1810 MHZ SIZ	21
	HF0AA3540A700 Elco (AVX)	SIGNAL CONDITIONING 3540 MHZ SIZ	35
	HF0AA6240A700 Elco (AVX)	SIGNAL CONDITIONING 6240 MHZ SIZ	35
	BP0FA1190A700 Elco (AVX)	RF FILTR BANDPASS 1.19GHZ 31ULGA	0
$LP0CA0550A7TR\250$	LP0CA0550A7TR\250 Elco (AVX)	RF FILTER LOW PASS 550MHZ 23ULGA	0
	LP0AA0149A700 Elco (AVX)	SIGNAL CONDITIONING 149 MHZ SIZE	35
	HF0BA1550A700 Elco (AVX)	SIGNAL CONDITIONING 1550 MHZ SIZ	28
$LP0805A2442ASTR\500$	LP0805A2442ASTR\500 Elco (AVX)	LOW PASS FILTER	0
	HF0AA4140A700 Elco (AVX)	SIGNAL CONDITIONING 4140 MHZ SIZ	0
	HF0BA1340A700 Elco (AVX)	SIGNAL CONDITIONING 1340 MHZ SIZ	0
	LP0AA0153A700 Elco (AVX)	SIGNAL CONDITIONING 153 MHZ SIZE	35
	BP0CA1100A700 Elco (AVX)	RF FILTER BANDPASS 1.1GHZ 23ULGA	0
	HF0DA0740A700 Elco (AVX)	SIGNAL CONDITIONING 740 MHZ SIZE	21
	LP0805A1960ASTR Elco (AVX)	LOW PASS FILTER	0
	LP0AA0299A700 Elco (AVX)	SIGNAL CONDITIONING 299 MHZ SIZE	35
	LP0FA0600A700 Elco (AVX)	SIGNAL CONDITIONING 600 MHZ SIZE	15
	BP0EA3180A700 Elco (AVX)	RF FILTR BANDPASS 3.18GHZ 30ULGA	0
	LP0805A0881ASTR Elco (AVX)	LOW PASS FILTER	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.