Part of the DoW SBIR/STTR FY27 Release 2 topic list. Browse all 83 topics by industry or service.
Topic DAF27BZ02-DV025 from the DoW SBIR 2027 BAA, Release 2. Pre-release now; proposals due January 6, 2027, 12:00 PM ET.
Quick answer
The Department of the Air Force wants miniature, low-power notch filters, each continuously tunable across at least 3 of the L, S, C, and X bands to reject large interferers, while passing 1 to 18 GHz to wideband EW, SigInt, and ESM receivers. This is a Direct-to-Phase II SBIR topic, and no Phase I award will be made. Proposals are due January 6, 2027, 12:00 PM ET.
Solicitation at a glance
- Topic number: DAF27BZ02-DV025
- Official title: Wide Pass Bandwidth, High Selectivity, Continuously Tunable Notch Filters
- Agency: Department of the Air Force
- Program: SBIR (DoW SBIR 2027 BAA, Release 2)
- Award type: Direct to Phase II (no Phase I awards)
- Award amount: Up to $2,000,000. Source: Department of the Air Force Release 2 instructions in DSIP.
- CMMC level: Level 2 (Self)
- ITAR: Yes. Export-controlled (ITAR/EAR); see topic text
- Technology areas: Battlespace, Electronics, Sensors
- Pre-release (direct TPOC contact allowed): November 4 to December 2, 2026, 8:00 AM ET
- Opens in DSIP: December 2, 2026, 8:00 AM ET
- Proposals due: January 6, 2027, 12:00 PM ET
- Official source: DSIP Topics app (search DAF27BZ02-DV025)
BW&CO's take
What the Department of the Air Force wants
Wideband receivers lack the dynamic range to capture weak signals next to large interferers, so platforms carry multiple receivers. The Air Force wants notch filters that remove those interferers. Each filter must pass 1 to 18 GHz with insertion loss or noise figure of 1.5 dB or less and IIP3 of +50 dBm or more, tune one notch continuously across at least 3 of the L, S, C, and X bands with at least 20 dB depth and 1% or less fractional bandwidth, handle interference above 5 dBm, fit in 3 cc, draw 100 mW or less, and cascade without interaction. Phase II delivers prototype filters.
Who is a good fit
- A lab-demonstrated tunable notch filter with a 20 dB deep notch, bandwidth under 5% of the tuned frequency, at least 3:1 continuous tuning, and passband loss below 3 dB.
- Tuning technology that achieves zero static power tuning in a volume near 1 cc.
- Measured data showing low passband distortion and high notch depth across all tuned states, plus tuning accuracy held over temperature.
- RF filter design experience for wideband receiver front ends used in EW, SigInt, or ESM.
Watch-outs
- Direct-to-Phase II: the proposal must document prior lab results (TRL 3) at the stated performance levels. A filter concept without measured data is unlikely to meet the bar.
- Two specs are easy to underplay: notch frequency accuracy within 50% of the notch bandwidth maintained over temperature, and multiple filters connected in series without interfering with one another.
- The topic metadata marks this topic as ITAR-restricted, so plan for export-control handling.
- The topic lists CMMC Level 2 (Self).
Think your company fits DAF27BZ02-DV025? Talk with BW&CO before the January 6 deadline.
Plan Your DAF27BZ02-DV025 Submission
Official topic text (verbatim from DSIP)
The text in this section is copied word for word from the official DSIP topic as published on November 4, 2026. DSIP is the official source and topics can be amended. Always confirm the current version at dodsbirsttr.mil before you submit. Our commentary above is BW&CO's interpretation, not Government guidance.
Title
Wide Pass Bandwidth, High Selectivity, Continuously Tunable Notch Filters
Objective
Wideband receivers used in electronic warfare (EW), signals intelligence (SigInt), and electronic support measures (ESM) need to instantaneously capture broad swaths of spectrum to avoid missing frequency agile radio frequency (RF) signals. Wideband receivers, however, lack the dynamic range to capture wide bandwidths of spectrum containing both large interferers and weak signals of interest. Thus, multiple receivers are needed in these applications which results in large size and power consumption.
Description
The objective of this topic is to develop miniature, low power, and high selectivity tunable notch filters capable of protecting wideband receivers from large interferers. The effort will target the largest interferers which are in L, S, C, and X bands with tunable notch filters, while allowing pass bandwidths spanning L through Ku bands. Each notch filter must be continuously tunable across a minimum of 3 of the 4 targeted bands (L, S, C, and X) while having a notch depth > 20 dB and a notch bandwidth < 1 % across all tuned frequencies. With a narrow notch bandwidth, each notch filter must be programmable and maintained with an accuracy of 50% of the notch bandwidth and should maintain this accuracy over temperature. The notch filters must be able to reject large interfering signals and therefore should be able to notch receive interference levels greater than 5 dBm. In the bandpass each filter must cover L-Ku band (1-18 GHz) while maintaining a low insertion loss and noise figure of less than 1.5 dB and low passband distortion with an IIP3 > +50 dBm. Each notch filter must be small, less than 3 cc, and should be connectable in series without interfering with one another to notch multiple frequencies in the same receive chain. Finally, the power consumption, including any tuning electronics, of each notch filter should be less than 100 mW. The required metrics are:
Passband frequency range (GHz)1 – 18
Maximum passband insertion loss or noise figure (dB) ≤ 1.5
Passband IIP3 (dBm)≥ 50
Notch band tunable frequency range (GHz)1 – 12
Number of bands covered by a single, continuously tunable notch≥ 3
Minimum notch depth across all tuned notch states (dB)≥ 20
Maximum notch fractional bandwidth (%)≤ 1Size (cc)≤ 3
Power consumption (mW)≤ 100
Phase I
This topic is intended for a technology proven ready to move directly into a Phase II program. A Phase I SBIR award will not be made. The offeror is required to provide details and documentation in the Direct to Phase II (D2P2) proposal which demonstrates accomplishments of a "Phase I-like" effort, including demonstrating the expertise needed to design and fabricate miniature, high selectivity tunable notch filters. The offeror should have demonstrated, in a laboratory environment (TRL3), a notch filter achieving a 20dB deep notch with a bandwidth less than 5% of the tuned frequency, a continuous tuning range of at least 3:1, and a passband insertion loss below 3 dB across a wide frequency range. Demonstration of zero static power tuning and a filter volume of approximately 1 cc is desired. The offeror should have demonstrated the capability of maintaining low passband distortion and high notch depth across all tuned states. The proposal should illustrate past success at the aforementioned performance levels with tunable notch filter technologies fitting the above descriptions
Phase II
The desired outcome of this topic is to demonstrate miniature, low power, and high selectivity tunable notch filters capable of protecting wideband receivers from large interferers. The effort will deliver prototype notch filters continuously tunable across a minimum of 3 of the 4 targeted bands (L, S, C, and X) while having a notch depth > 20 dB and a notch bandwidth < 1 % across all tuned frequencies.
Phase III Dual Use Applications
Phase III is accomplished when the DoW and/or commercial applications of this SBIR-funded R&D are developed using non-SBIR/STTR funds. The most direct military application is the integration of these miniature, continuously tunable notch filters into the RF front ends of wideband receivers used for electronic warfare (EW), signals intelligence (SigInt), and electronic support measures (ESM). By selectively rejecting large interferers and jammers in L, S, C, and X bands while preserving reception across the full L–Ku passband, the filters enable a single high-dynamic-range wideband receiver to replace multiple narrowband receivers, directly reducing platform size, weight, and power. Additional DAF and DoW transition opportunities include receiver protection in airborne and ground-based radar systems, jam-hardened wideband communications and SATCOM-on-the-move terminals, and reconfigurable RF front ends for software-defined radios, where the same look-through capability allows the system to respond to threat pulses without missing frequency-hopped waveforms. Potential commercial applications include interference mitigation for 5G systems operating adjacent to incumbent services (such as C-band interference into radio altimeters and co-channel interference in cellular receivers), test and measurement instrumentation, and spectrum-monitoring equipment, all markets where compact, low-power, high-selectivity tunable filtering is increasingly required as the spectrum becomes more congested. The expected Phase III effort would advance the technology from its Phase II exit point of TRL5 toward TRL7 and beyond through integration into a host receiver subsystem, environmental qualification to applicable military standards, and demonstration in a relevant operational environment. This effort would also include maturation of the manufacturing process to support production quantities, screening and reliability testing, and the establishment of a qualified supply chain. Transition planning anticipates partnership with a DoW prime contractor or system integrator as the host platform sponsor, with the small business supplying the notch filter as a component or subassembly. Known government activities required prior to fielding include security classification review, ITAR/export-control determination, and any platform-specific airworthiness or system certification associated with the selected transition host. Early engagement with DAF program offices, EW and SigInt system developers, and additional DoW customers during Phase II is recommended to identify a committed transition partner and to align the filter's form factor and interface with the targeted receiver architecture.
References
J. Roessler, E. Lever, A. Egbert, C. Baylis, R. Marks, B. Kirk, and A. Bouvy, "Overview of Tunable Notch Filters for Radar Systems," 2024. doi: available via IEEE Xplore (document 10619014).
F. Lin and M. Rais-Zadeh, "Tunable RF MEMS Filters: A Review," in Encyclopedia of Nanotechnology, B. Bhushan, Ed. Dordrecht: Springer, 2015. doi: 10.1007/978-94-007-6178-0_100959-1
Reines, S.-J. Park, I. El-Tanani, A. Grichener, and G. M. Rebeiz, "Compact Low-Loss Tunable X-Band Bandstop Filter With Miniature RF-MEMS Switches, "IEEE Transactions on Microwave Theory and Techniques, vol. 58, no. 7, pp. 1887–1895, Jul. 2010.
M. Fernández-Bolaños, C. Dehollain, P. Nicole, and A. M. Ionescu, "Tunable band-stop filter based on single RF MEMS capacitive shunt switch with meander arm inductance, "Solid-State Electronics, vol. 54, no. 9, pp. 1033–1040, 2010. doi: 10.1016/j.sse.2010.04.030.
L. Wang, T. Du, et al., "High-selectivity wideband bandpass filter with tunable notched band,"AEU – International Journal of Electronics and Communications, 2025.
D. Mardivirin, F. Barrière, A. Pothier, A. Crunteanu, and P. Blondy, "A 2 Pole 9.6–11.7 GHz Band Stop Filter Using Analog Tuning RF MEMS Varactors," inProc. 2011 European Microwave Integrated Circuits Conf. (EuMIC), Manchester, UK, Oct. 2011, pp. 530–533.
Analog Devices, "How Digitally Tunable Filters Enable Wideband Receiver Applications, "Analog Dialogue. [Online]. Available: https://www.analog.com/en/resources/analog-dialogue/articles/how-digitally-tunable-filters-enable-wideband-receiver-applications.html
Keywords
Tunable Filter; Notch Filter
Frequently asked questions
What is DAF27BZ02-DV025?
A Department of the Air Force topic in the DoW SBIR 2027 BAA titled Wide Pass Bandwidth, High Selectivity, Continuously Tunable Notch Filters. It seeks small, low-power notch filters that protect wideband receivers from large interferers.
When is DAF27BZ02-DV025 due?
Proposals are due January 6, 2027, 12:00 PM ET. DSIP pre-release began November 4, 2026, and direct contact with the topic authors (TPOCs) is allowed only until the topic opens on December 2, 2026, 8:00 AM ET.
Is DAF27BZ02-DV025 Phase I or Direct-to-Phase II?
Direct-to-Phase II. A Phase I SBIR award will not be made. The proposal must document a Phase I-like effort, including expertise designing and fabricating miniature, high selectivity tunable notch filters.
What are the required notch filter metrics?
Passband 1 to 18 GHz, passband insertion loss or noise figure of 1.5 dB or less, passband IIP3 of 50 dBm or more, notch tuning range 1 to 12 GHz covering at least 3 bands with one continuously tunable notch, notch depth of 20 dB or more, notch fractional bandwidth of 1% or less, size of 3 cc or less, and power consumption of 100 mW or less.