FSF-5050-387M5 / 388M / 388M5 IF SAW Filter Family

Q: Q1: How should I choose between FSF-5050-387M5, FSF-5050-388M and FSF-5050-388M5?

A1: If your IF is planned around 387.5 MHz and you prefer a slightly wider passband to tolerate frequency offsets or multiple modes, FSF-5050-387M5 is a good choice. For IF at 388 MHz with medium bandwidth and good adjacent channel rejection, choose FSF-5050-388M. If your spectrum mask is tighter and you require stronger adjacent-channel and image rejection around ~388.5 MHz, FSF-5050-388M5 is recommended. You can also share your block diagram and spectral requirements with FCom and we will help you select the best option.

Q: Q2: Do these IF SAW filters require external matching networks?

A2: The family is designed for nominal 50 Ω in/out. If your surrounding circuits are also 50 Ω, the filter can usually be used in a direct series configuration. If the actual impedance deviates from 50 Ω or you want to fine-tune the passband shape, a small L/C matching network can be added. FCom can provide S-parameter files and application notes to help you optimize the matching in your simulation tools.

Q: Q3: Any PCB layout and grounding tips for best performance?

A3: Place the SAW filter directly in the critical IF signal path, as close as possible to the previous and next amplifier stages. Use a continuous ground plane underneath with multiple ground vias around the device to reduce parasitics. Keep input and output traces controlled at 50 Ω and avoid long detours and sharp bends. Do not route high-speed clocks, DC-DC switching nodes or large-current traces in parallel close to the SAW filter to minimize coupling.

Q: Q4: Are FSF-5050-387M5 / 388M / 388M5 suitable for harsh temperature and reliability conditions?

A4: The family supports industrial temperature ranges such as -30 °C / -40 °C to +85 °C with stable frequency and long-term reliability, which covers most industrial and communication applications. For wider temperature ranges or specific military/automotive requirements, please contact FCom to discuss suitable part numbers or custom options.

FSF-5050-387M5, FSF-5050-388M and FSF-5050-388M5 are FCom Fuji Crystal’s 5.0×5.0 mm IF SAW filters with center frequencies around 387.5 MHz, 388 MHz and 388.5 MHz. With 50 Ω interfaces, low insertion loss and strong stopband rejection, they are ideal for IF chains and high-performance RF front-end designs across different standards and spectrum plans.

5.0×5.0 mm SMD IF SAW filter 387.5 / 388 / 388.5 MHz 50 Ω interface Low insertion loss

Typical applications: IF stages in radio receivers, microwave and point-to-point links, professional wireless systems, telemetry and monitoring equipment, and test & measurement instruments.

Request RFQ / Samples / Custom Back to SAW filter list

FSF-5050-387M5 / 388M / 388M5 IF SAW filters in 5.0×5.0 mm package

Product Overview & Key Features

The FSF-5050-387M5 / 388M / 388M5 family is designed for intermediate-frequency (IF) signal processing. Each part uses a standard 5.0×5.0 mm SMD package with nominal 50 Ω input and output impedance, enabling direct interfacing with common RF / IF amplifiers and transceiver ICs. This simplifies matching networks, shortens design time and improves system repeatability.

Three IF frequency options: ~387.5 MHz, 388 MHz and ~388.5 MHz for different systems.
Typical insertion loss in the 2–3 dB range, balancing selectivity and receiver sensitivity.
Well-controlled in-band ripple for high dynamic range and higher-order modulation schemes.
High stopband attenuation around adjacent and image frequencies to reduce interference.
50 Ω input/output interface, 5.0×5.0 mm SMD package for easy SMT and module integration.
RoHS compliant, lead-free construction for industrial and communication equipment.

Target Systems / Standards & Typical IF Placement

These filters are typically placed in the IF chain after downconversion (mixer) and before/after IF gain stages, where adjacent-channel suppression and image rejection directly impact sensitivity and dynamic range. Common target systems include professional wireless receivers, microwave/point-to-point links, spectrum monitoring/telemetry, and test instrumentation.

Explore Other FSF-5050 IF SAW Filter Families

For different IF frequencies or passband widths, you can also consider the following 5.0×5.0 mm SAW filter families:

Typical Electrical Specifications

The table below summarizes the main parameters of the three frequency options. Actual values may vary slightly with process and measurement conditions and should be confirmed in the official datasheet and S-parameter files for your design.

Center frequency

387.5 / 388 / 388.5 MHz

Impedance

50 Ω in / 50 Ω out

Package

5.0×5.0 mm, 8-pin SMD

Value focus

Low loss + high stopband

Test note (guidance): verify insertion loss, ripple and matching in your setup (50 Ω fixtures, calibrated VNA; de-embed when needed).

Matching / Impedance Notes

The family is designed for nominal 50 Ω source/load. If surrounding stages deviate from 50 Ω or you need passband shaping, add a small L/C network and validate using S-parameters in your RF simulator.

Parameter	FSF-5050-387M5	FSF-5050-388M	FSF-5050-388M5
Center frequency Fc	~387.5 MHz	388 MHz	~388.5 MHz
Package size	5.0 × 5.0 mm SMD, standard 8-pin layout
Nominal impedance	50 Ω input / 50 Ω output
Typical passband	-	~384 – 392 MHz medium bandwidth	~386.5 – 390.5 MHz narrower IF bandwidth
Insertion loss (typ.)	-	~2.3 dB	~2.0 dB
In-band ripple (typ.)	-	< ~0.8 dB	< ~0.7 dB
Input / output VSWR (typ.)	-	≤ ~1.8 : 1	Optimized for 50 Ω matching
Stopband attenuation	-	High attenuation at adjacent and image frequencies	Optimized for tighter spectral mask compliance
Operating temperature (ref.)	-	-40 °C to +85 °C	-40 °C to +85 °C
Temperature coefficient (typ.)	~ -36 ppm/°C
Environmental	RoHS compliant, lead-free package

Note: Values above are representative typical numbers. For precise design work, please refer to the official FCom Fuji Crystal datasheet and request S-parameter files from our sales or FAE team.

Typical Applications

Radio & Professional Two-Way IF Stages

Used as IF filters in receiver chains to suppress image and adjacent channels, improving selectivity and interference immunity for professional radios and digital two-way systems.

Microwave & Point-to-Point Links

Suitable for IF modules in fixed wireless access, microwave backhaul and point-to-point links, ensuring spectral purity and adjacent-channel rejection for high data rate and higher-order modulation.

Test, Monitoring & Telemetry Systems

Ideal for spectrum monitoring, telemetry, remote sensing and measurement instruments where stable and repeatable IF filtering is required for accurate results.

RF Front Ends & Modular Designs

Can be integrated into RF front-end modules and OEM sub-systems along with FCom crystals, TCXOs and OCXOs to build a complete timing and filtering solution.

For special IF frequency plans or customized passband/stopband requirements, FCom can support other FSF-5050 variants or custom SAW filter development. Please contact us with your system diagram and specification.

Related Application Guide

SAW Filters for Professional Wireless Receivers: Engineering Guide

Learn More: SAW Filter Design & Selection

Ordering Code / Options

This family covers three common IF plans around 387.5 MHz, 388 MHz and 388.5 MHz in a 5.0×5.0 mm SMD footprint. For tighter masks, different passbands, or customized stopband targets, FCom can support variant selection and custom development. Supply modes typically include samples, volume production, and customized specifications upon request.

Selection Path / Upgrade Options

Need a lower IF plan nearby: FSF-5050-340M~345M, FSF-5050-352M~354M5
Need a higher IF plan nearby: FSF-5050-390M~394M, FSF-5050-400M~408M5, FSF-5050-413M~415M4

Contact for RFQ / Lead time / MOQ Downloads

Documents & Downloads

Datasheets

Support

Request S-parameters, test reports, and matching guidance via Contact.
ISO certifications: ISO9001, ISO14001

FSF-5050-387M5/388M/388M5 IF SAW filter package outline

Package outline (reference drawing).

Frequently Asked Questions (FAQ)

Q1: How should I choose between FSF-5050-387M5, FSF-5050-388M and FSF-5050-388M5?

A1: If your IF is planned around 387.5 MHz and you prefer a slightly wider passband to tolerate frequency offsets or multiple modes, FSF-5050-387M5 is a good choice. For IF at 388 MHz with medium bandwidth and good adjacent channel rejection, choose FSF-5050-388M. If your spectrum mask is tighter and you require stronger adjacent-channel and image rejection around ~388.5 MHz, FSF-5050-388M5 is recommended. You can also share your block diagram and spectral requirements with FCom and we will help you select the best option.

Q2: Do these IF SAW filters require external matching networks?

A2: The family is designed for nominal 50 Ω in/out. If your surrounding circuits are also 50 Ω, the filter can usually be used in a direct series configuration. If the actual impedance deviates from 50 Ω or you want to fine-tune the passband shape, a small L/C matching network can be added. FCom can provide S-parameter files and application notes to help you optimize the matching in your simulation tools.

Q3: Any PCB layout and grounding tips for best performance?

A3: Place the SAW filter directly in the critical IF signal path, as close as possible to the previous and next amplifier stages. Use a continuous ground plane underneath with multiple ground vias around the device to reduce parasitics. Keep input and output traces controlled at 50 Ω and avoid long detours and sharp bends. Do not route high-speed clocks, DC-DC switching nodes or large-current traces in parallel close to the SAW filter to minimize coupling.

Q4: Are FSF-5050-387M5 / 388M / 388M5 suitable for harsh temperature and reliability conditions?

A4: The family supports industrial temperature ranges such as -30 °C / -40 °C to +85 °C with stable frequency and long-term reliability, which covers most industrial and communication applications. For wider temperature ranges or specific military/automotive requirements, please contact FCom to discuss suitable part numbers or custom options.

Q5: Do you publish pricing online? How do I request a quote (RFQ)?

A5: Pricing is quotation-based (configuration, volume, lead time and test requirements). Send your target center frequency, bandwidth/mask, temperature range, and annual usage via Contact to request an RFQ.

Q6: MOQ, lead time, and sample availability?

A6: MOQ and lead time depend on the exact part number and production schedule. Samples are typically available for evaluation, and volume supply is supported for qualified projects. Contact FCom with your quantity and timeline to confirm the current lead time and sample plan.

Q7: Can you customize passband/stopband or provide test reports?

A7: Yes. Custom center frequency, bandwidth, ripple targets, and stopband constraints can be discussed for design-in projects. Upon request, FCom can support documentation such as datasheets, measurement conditions, and relevant test data for qualification.