Coaxial Band Pass Filter
Coaxial Band Pass Filter allows signals within a defined frequency band to pass while rejecting unwanted frequencies. Ideal for RF communication systems, radar receivers, satellite communication modules and microwave equipment.
High-Q Coaxial Band Pass Filters for Sharp Out-of-Band Rejection
AO Microwave’s high-selectivity coaxial band pass filters are engineered to isolate designated frequency bands while providing steep rejection of out-of-band interference up to 40 GHz. Built with precision-machined aluminum and copper cavity housings, these filters utilize high-Q combline or interdigital resonator structures. Featuring gold-plated beryllium copper tuning screws and low-expansion Invar elements to minimize temperature-induced frequency drift, our coaxial band pass filters achieve low insertion losses (typically < 1.0 dB in narrow-band models) and an exceptional input VSWR of < 1.25:1 across the passband.
By establishing a highly selective spectral window, our cavity filters suppress harmonic and spurious signals with high rejection levels (typically > 60 dB). They are critical for co-site interference mitigation in military communications, radar receiver front-ends, and satellite transceiver multiplexers.
| Part No | Frequency/GHz | Center Frequency/GHz | VSWR (Max) | IL/dB (Max) | Stopband Rejection/dB (Min) |
| AO62.5M77.5M-CBPF-SK | 0.0625-0.0775 | 0.07 | 1.50 | 2.0 | 40dB@DC-50MHz 40dB@90-500MHz |
| AO140M232M-CBPF-SK | 0.14-0.232 | 0.186 | 1.40 | 2.5 | 40dB@DC-125MHz 40dB@260-600MHz |
| AO703M748M-CBPF-SK | 0.703-0.748 | 0.7255 | 1.50 | 5.0 | 40dB@758MHz |
| AO758M803M-CBPF-SK | 0.758-0.803 | 0.7805 | 1.50 | 3.0 | 60dB@2F0GHz 50dB@3F0GHz |
| AO791M821M-CBPF-SK | 0.791-0.821 | 0.806 | 1.50 | 3.0 | 60dB@2F0GHz 50dB@3F0GHz |
| AO814M849M-CBPF-SK | 0.814-0.849 | 0.8315 | 1.50 | 5.0 | 40dB@859MHz |
| AO0.85G1.55G-CBPF-SK | 0.85-1.55 | 1.2 | 1.50 | 3.0 | 60dB@DC-500MHz 45dB@2-3GHz |
| AO880M915M-CBPF-SK | 0.88-0.915 | 0.897 | 1.50 | 4.0 | 40dB@925MHz |
| AO1.1G1.67G-CBPF5-SK | 1.1-1.67 | 1.385 | 1.80 | 1.5 | 80dB@DC-1GHz 20dB@1.7GHz |
| AO1.3G2.43G-CBPF-SK | 1.3-2.43 | 1.865 | 1.70 | 1.5 | 70dB@DC-1GHz 50dB@2.8GHz |
| AO1.71G1.785G-CBPF-SK | 1.71-1.785 | 1.7475 | 1.50 | 4.5 | 50dB@1.805GHz |
| AO1.805G1.88G-CBPF-SK | 1.805-1.88 | 1.8425 | 1.50 | 2.5 | 60dB@2F0GHz 50dB@3F0GHz |
| AO1.85G1.915G-CBPF-SK | 1.85-1.915 | 1.8825 | 1.50 | 5.0 | 40dB@1.93GHz |
| AO1.92G2.01G-CBPF-SK | 1.92-2.01 | 1.965 | 1.50 | 3.0 | 60dB@2.11GHz |
| AO1.93G1.995G-CBPF-SK | 1.93-1.995 | 1.9625 | 1.50 | 3.0 | 60dB@2F0GHz 50dB@3F0GHz |
| AO2.099G2.101G-CBPF-SK | 2.099-2.101 | 2.1 | 1.30 | 5.0 | 50dB@DC-2.085GHz 50dB@2.115GHz |
| AO2.11G2.2G-CBPF-SK | 2.11-2.2 | 2.155 | 1.50 | 3.0 | 60dB@2F0GHz 50dB@3F0GHz |
| AO2G3.8G-CBPF-SK | 2-3.8 | 2.9 | 2.00 | 2.5 | 20dB@1.85GHz 20dB@3.95GHz |
| AO2G18G-CBPF-SK | 2-18 | 10 | 1.80 | 3.5 | 30dB@18.75GHz 50dB@19-40GHz |
| AO2.5G4G-CBPF-SK | 2.5-4 | 3.25 | 1.70 | 1.0 | 65dB@DC-2.2GHz 55dB@4.3-8GHz |
| AO3.2G4.5G-CBPF-SK | 3.2-4.5 | 3.85 | 1.50 | 0.5 | 60dB@DC-2.4GHz 50dB@5.5GHz |
| AO3G5G-CBPF-SK | 3-5 | 4 | 1.70 | 1.0 | 40dB@DC-2.5GHz 40dB@5.5GHz |
| AO3.7G4.5G-CBPF-SK | 3.7-4.5 | 4.1 | 1.80 | 1.0 | 50dB@DC-3.15GHz 50dB@5.05GHz |
| AO4G6G-CBPF-SK | 4-6 | 5 | 1.50 | 0.8 | 60dB@DC-3.2GHz 55dB@7GHz |
| AO4G6G-CBPF-SK-A2 | 4-6 | 5 | 1.50 | 0.7 | 60dB@DC-3.2GHz 60dB@6.5-12GHz |
| AO4G8G-CBPF-SK | 4-8 | 6 | 1.50 | 0.8 | 75dB@DC-3.5GHz 65dB@8.5GHz |
| AO4.9G8G-CBPF-SK | 4.9-8 | 6.45 | 1.70 | 1.5 | 40dB@3.9GHz 65dB@12.8-15GHz |
| AO6G8.5G-CBPF-SK | 6-8.5 | 7.25 | 1.80 | 1.3 | 60dB@DC-5.2GHz 60dB@9.5GHz |
| AO6G12G-CBPF-SK | 6-12 | 9 | 1.70 | 1.0 | 30dB@DC-5.5GHz 35dB@13-20GHz |
| AO6.8G10.65G-CBPF-SK | 6.8-10.65 | 8.725 | 1.50 | 1.0 | 60dB@DC-6.4GHz 25dB@10.85GHz |
| AO7G9G-CBPF-SK | 7-9 | 8 | 1.70 | 1.0 | 40dB@DC-6.5GHz 40dB@9.5GHz |
| AO7.5G12.5G-CBPF-SK | 7.5-12.5 | 10 | 1.70 | 1.0 | 45dB@DC-6.5GHz 55dB@14GHz |
| AO8G16G-CBPF-SK | 8-16 | 12 | 1.60 | 0.7 | 80dB@DC-6.5GHz 50dB@17.5GHz |
| AO9G12G-CBPF-SK | 9-12 | 10.5 | 1.50 | 0.8 | 40dB@DC-8.5GHz 30dB@12.5GHz |
| AO8.5G10.65G-CBPF-SK | 8.5-10.65 | 9.575 | 1.50 | 1.0 | 80dB@DC-6.5GHz 52dB@10.85GHz |
| AO9G12G-CBPF-SK | 9-12 | 10.5 | 1.50 | 0.8 | 40dB@DC-8.5GHz 30dB@12.5GHz |
| AO9G13.25G-CBPF-SK | 9-13.25 | 11.125 | 1.80 | 2.0 | 70dB@DC-8.4GHz 30dB@13.5GHz |
| AO10G15G-CBPF-SK | 10-15 | 12.5 | 1.50 | 1.0 | 60dB@DC-8GHz 60dB@18GHz |
| AO11G14G-CBPF-SK | 11-14 | 12.5 | 1.70 | 1.5 | 40dB@9.5GHz 65dB@15.8-25GHz |
| AO11.7G13.7G-CBPF-SK | 11.7-13.7 | 12.7 | 1.70 | 0.8 | 60dB@DC-10.5GHz 60dB@15.2GHz |
| AO12G15G-CBPF-SK | 12-15 | 13.5 | 1.50 | 0.8 | 35dB@DC-11.5GHz 30dB@15.5GHz |
| AO12G16G-CBPF-SK | 12-16 | 14 | 1.70 | 1.0 | 60dB@DC-10.5GHz 60dB@17.5GHz |
| AO13.2G15.9G-CBPF-SK | 13.2-15.9 | 14.55 | 1.50 | 1.0 | 50dB@11.9GHz 30dB@16.5GHz |
| AO13.8G15.2G-CBPF-SK | 13.8-15.2 | 14.15 | 1.30 | 0.8 | 60dB@DC-12GHz 60dB@17GHz |
| AO14G18G-CBPF-SK | 14-18 | 16 | 1.80 | 2.5 | 50dB@9.3GHz 50dB@23GHz |
| AO14.5G20G-CBPF-SK | 14.5-20 | 17.25 | 2.00 | 2.0 | 60dB@DC-12GHz 60dB@22.5-30GHz |
| AO14.8G15.8G-CBPF-SK | 14.8-15.8 | 15.3 | 1.50 | 1.0 | 70dB@DC-12.4GHz 70dB@17.5GHz |
| AO16G18G-CBPF-SK | 16-18 | 17 | 1.50 | 1.0 | 60dB@DC-15GHz 60dB@19GHz |
| AO16G20G-CBPF-SK | 16-20 | 18 | 1.80 | 1.0 | 50dB@DC-15GHz |
| AO17G18G-CBPF-SK | 17-18 | 17.5 | 1.40 | 1.0 | 70dB@DC-15.5GHz 70dB@19.5GHz |
| AO17.6G21.5G-CBPF-SK | 17.6-21.5 | 19.55 | 1.50 | 1.0 | 60dB@DC-16GHz 60dB@22.5-30GHz |
| AO18G19G-CBPF-SK | 18-19 | 18.5 | 1.40 | 1.2 | 65dB@DC-16.5GHz 65dB@20.5GHz |
| AO18G22G-CBPF-SK | 18-22 | 20 | 2.00 | 2.5 | 30dB@16GHz 30dB@24GHz |
| AO18G26.5G-CBPF-SK | 18-26.5 | 22.25 | 1.50 | 1.5 | 60dB@DC-16.5GHz 60dB@27GHz |
| AO18G40G-CBPF-SK | 18-40 | 29 | 2.60 | 2.0 | 50dB@DC-15GHz |
| AO18.4G18.8G-CBPF-SK | 18.4-18.8 | 18.6 | 1.40 | 1.0 | 60dB@DC-17GHz 40dB@20GHz |
| AO19G20.5G-CBPF-SK | 19-20.5 | 19.75 | 1.40 | 1.5 | 70dB@DC-17.4GHz 60dB@22-41GH |
| AO19.5G21.2G-CBPF-SK | 19.5-21.2 | 20.35 | 1.40 | 2.0 | 70dB@DC-18.3GHz 60dB@22-28GHz |
| AO20G40G-CBPF-2.92K | 20-40 | 30 | 2.40 | 2.0 | 60dB@DC-15GHz |
| AO20.6G21.6G-CBPF-SK | 20.6-21.6 | 21.1 | 1.40 | 1.0 | 60dB@DC-18.3GHz 60dB@24GHz |
| AO21.5G22.5G-CBPF-SK | 21.5-22.5 | 22 | 1.30 | 2.0 | 60dB@DC-20.5GHz 60dB@23.5-40GHz |
| AO24G25G-CBPF-SK | 24-25 | 24.5 | 1.50 | 3.0 | 60dB@DC-23.5GHz 60dB@25.5-50GHz |
| AO24.6G27.6G-CBPF-2.92K | 24.6-27.6 | 26.1 | 1.50 | 3.0 | 60dB@DC-22.5GHz 55dB@28.5-48GHz |
| AO24.9G26.6G-CBPF-2.92K | 24.9-26.6 | 25.75 | 1.60 | 2.0 | 60dB@DC-24GHz 55dB@27.5-48GHz |
| AO25G26G-CBPF-2.92K | 25-26 | 25.5 | 1.80 | 3.0 | 70dB@DC-23.5GHz 70dB@27.5GHz |
| AO27.75G28.25G-CBPF-2.92K | 27.75-28.25 | 28 | 1.50 | 2.0 | 40dB@DC-27.5GHz 40dB@28.5GHz |
| AO29.196G29.241G-CBPF-2.92K | 29.196-29.241 | 29.2185 | 1.50 | 2.8 | 40dB@DC-29GHz 40dB@29.5-40.4GHz |
| AO29.3G30.3G-CBPF-2.92K | 29.3-30.3 | 29.7 | 1.80 | 3.0 | 60dB@DC-28GHz 60dB@31.5GHz |
| AO30G40G-CBPF-2.92K | 30-40 | 35 | 2.00 | 2.0 | 75dB@DC-27GHz 75dB@45-55GHz |
| AO30.2G31G-CBPF-2.92K | 30.2-31 | 30.6 | 1.40 | 1.0 | 60dB@DC-28.5GHz 60dB@33.5-48GHz |
| AO32G35G-CBPF-2.92K | 32-35 | 33.5 | 1.60 | 1.8 | 55dB@DC-31GHz 50dB@36-40GHz |
| AO34G40G-CBPF-2.92K | 34-40 | 36 | 2.00 | 1.2 | 50dB@DC-31GHz |
| AO35.4G35.6G-CBPF-2.92K | 35.4-35.6 | 35.5 | 1.50 | 4.0 | 70dB@DC-34.8GHz 70dB@36.3GHz |
| AO38.75G39.25G-CBPF-2.92K | 38.75-39.25 | 28 | 1.50 | 2.5 | 40dB@DC-38.3GHz 40dB@39.7GHz |
Understanding Cavity Q-Factor & Temperature Compensation
Cavity band pass filters achieve high selectivity through physical resonance. However, the aluminum housings expand and contract with temperature variations, shifting the resonant cavity dimensions and causing center frequency (f0) drift.
To stabilize the frequency response, AO Microwave incorporates Invar tuning elements inside the cavity resonators. Invar exhibits an extremely low thermal expansion coefficient (typically < 1.2 ppm/°C). When matched against the expanding aluminum housing, the Invar rods compensate for dimensional shifts, keeping the center frequency drift below 2 ppm/°C. This design maintains low insertion loss and high selectivity across wide operating temperatures.
Target Applications & Operational Advantages
By providing high selectivity and low insertion loss, our coaxial cavity band pass filters secure critical signal paths:
Co-Site Transmitter Clean-up
Function: Placed at the output of high-power transmitters to suppress out-of-band spurious emissions and harmonics.
Advantage: Sharp rejection (>60 dB) prevents transmitter noise from blinding adjacent sensitive receivers, while handling high continuous power.
Radar Receiver Front-Ends
Function: Filters received signals at the radar antenna interface before amplification by the LNA.
Advantage: Extremely low insertion loss (<0.5 dB in wideband models) preserves system noise figure, maximizing radar detection range.
Satellite Ground Station Multiplexers
Function: Separates closely spaced transmit and receive channels in satcom transponders.
Advantage: Steep roll-off selectivity provides excellent isolation between guard bands, preventing cross-channel interference.
Coaxial Band Pass Filter FAQs
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