Intermediate Frequency (IF) Filter

Product Specifications

Technical details and manufacturing context for Intermediate Frequency (IF) Filter

Definition

The Intermediate Frequency (IF) Filter is a critical component in superheterodyne receiver circuits, used to filter and process signals after frequency conversion to the intermediate frequency (IF). Its primary function is to remove unwanted frequencies, reduce noise, and improve signal selectivity before demodulation. This filter operates by allowing signals within a specific frequency band (the intermediate frequency) to pass through while attenuating signals outside this band, using resonant circuits, ceramic filters, or SAW filters to achieve precise frequency selection and rejection. Typical parameters include a center frequency of 455 kHz for AM receivers, a bandwidth ranging from 10 to 500 kHz, insertion loss of 1 to 6 dB, passband ripple of ≤1 dB, stopband rejection of ≥40 dB, impedance of 50 to 75 ohms, operating temperature from -40 to 85°C, storage temperature from -55 to 125°C, humidity up to 95% RH (non-condensing), power handling of 0.1 to 1 W, and a surface-mount package (SMD) with dimensions of 3.2×2.5×1.2 mm and weight of 0.05 to 0.2 g. Materials commonly used include ceramic, quartz, and piezoelectric materials. These values are typical reference ranges and must be verified for the specific model and application with the legal manufacturer or supplier. The filter is essential for achieving the desired selectivity and sensitivity in radio receivers, and its performance directly impacts the quality of the received signal. Proper selection requires consideration of the system's impedance, bandwidth requirements, and environmental conditions. Maintenance signals include degradation in signal quality, increased insertion loss, or frequency drift, which may indicate the need for replacement. The filter is designed for use within specified electrical and environmental limits; exceeding these limits can cause permanent damage.

Working Principle

The IF filter operates by exploiting the frequency-selective properties of resonant circuits, ceramic resonators, or surface acoustic wave (SAW) devices. It presents a low impedance to signals within its passband, allowing them to pass with minimal attenuation, while presenting a high impedance to signals outside the passband, thereby attenuating them. The center frequency and bandwidth are determined by the physical dimensions and material properties of the filter elements. For example, ceramic filters use piezoelectric materials that vibrate at specific frequencies, while SAW filters use interdigital transducers on a piezoelectric substrate to convert electrical signals to acoustic waves and back, providing sharp frequency selectivity. The filter's performance is characterized by parameters such as insertion loss, passband ripple, and stopband rejection, which are specified by the manufacturer. The filter must be impedance-matched to the surrounding circuitry to minimize reflections and ensure optimal signal transfer.

Common Materials

Ceramic, Quartz, Piezoelectric materials

Technical Parameters

Parameter	Typical range	Notes & selection driver
Center Frequency	455 kHz	Typical IF for AM receivers
Bandwidth	10–500 kHz	Selectivity vs. signal fidelity trade-off
Insertion Loss	1–6 dB	Lower is better for signal strength
Passband Ripple	≤1 dB	Affects amplitude flatness
Stopband Rejection	≥40 dB	Attenuation of out-of-band signals
Impedance	50–75 Ω	Match to system impedance
Operating Temperature	-40–85 °C	Extended range for industrial use
Storage Temperature	-55–125 °C	Non-operating survival
Humidity	0–95 % RH	Non-condensing
Power Handling	0.1–1 W	Maximum input power without damage
Package Type	SMD	Surface mount for automated assembly
Dimensions	3.2×2.5×1.2 mm	Typical SMD footprint
Weight	0.05–0.2 g	Lightweight for portable devices

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Resonator
Creates resonance at the intermediate frequency to enable filtering

Material: Ceramic or quartz
Electrodes Part
Apply electrical signals to and extract signals from the resonator

Material: Metal (typically gold or aluminum)
Package/Casing Part
Protects the filter from environmental factors and provides electrical connections

Material: Plastic or ceramic
Interdigital Transducers Optional
Convert between electrical signal and surface acoustic wave on SAW-type filters.

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Intermediate Frequency (IF) Filter.

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Receiver Circuit

View system integration details

Manufacturers of Intermediate Frequency (IF) Filter

Manufacturer profiles associated with Intermediate Frequency (IF) Filter.

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review · Page last updated 6 September 2026

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Frequently Asked Questions

What is the typical center frequency for an IF filter in AM receivers?

The typical center frequency for AM receivers is 455 kHz, as listed in the reference parameters. However, actual values may vary depending on the specific application and design.

What materials are commonly used in IF filters?

Common materials include ceramic, quartz, and piezoelectric materials. These materials enable precise frequency selection and are used in ceramic filters, crystal filters, and SAW filters.

What does insertion loss indicate?

Insertion loss is the amount of signal power lost when passing through the filter. Lower values are generally better for signal strength. The reference range is 1 to 6 dB, but you should verify the specific value for your model.

Can IF filters be used in surface-mount technology (SMT) assembly?

Yes, the reference package type is SMD (surface-mount device), which is suitable for automated assembly. The typical dimensions are 3.2×2.5×1.2 mm, but always confirm the exact footprint with the supplier.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	Atmospheric pressure only (sealed package)
other spec:	Frequency range: 455 kHz to 10.7 MHz typical, Insertion loss: <3 dB, VSWR: <2:1
temperature:	-40°C to +85°C (operational), -55°C to +125°C (storage)

Product Specifications

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