| Image | Part Number | Description / PDF | Quantity | Rfq |
|---|---|---|---|---|
 |
HELICAL FILTER 1.015GHZ CENTER |
346 |
|
|
 |
HELICAL FILTER 813MHZ CENTER |
26 |
|
|
 |
HELICAL FILTER 830MHZ CENTER |
22 |
|
|
 |
HELICAL FILTER 405MHZ CENTER |
166 |
|
|
 |
HELICAL FILTER 223MHZ CENTER |
221 |
|
|
 |
HELICAL FILTER 365MHZ CENTER |
790 |
|
|
 |
HELICAL FILTER 440MHZ CENTER |
119 |
|
|
 |
HELICAL FILTER 456MHZ CENTER |
703 |
|
|
 |
HELICAL FILTER 933MHZ CENTER |
1315 |
|
|
 |
HELICAL FILTER 360MHZ CENTER |
40 |
|
|
 |
HELICAL FILTER 820MHZ CENTER |
112 |
|
|
 |
HELICAL FILTER 915MHZ CENTER |
6414 |
|
|
 |
HELICAL FILTER 515MHZ CENTER |
24 |
|
|
 |
HELICAL FILTER 914MHZ CENTER |
70 |
|
|
 |
HELICAL FILTER 360MHZ CENTER |
300 |
|
Helical filters are a type of bandpass filter utilizing helical resonators to achieve high-quality factor (Q) performance in compact RF/microwave systems. These filters employ spiral-shaped transmission lines to create electromagnetic coupling, enabling precise frequency selection. Their importance in modern technology stems from their ability to provide stable filtering performance in wireless communication systems, radar, and test equipment while maintaining mechanical robustness and thermal stability.
| Type | Functional Characteristics | Application Examples |
|---|---|---|
| Fixed Frequency Helical | Stable center frequency with high Q-value | 5G base stations |
| Adjustable Helical | Variable bandwidth and center frequency tuning | Field measurement equipment |
| Wideband Helical | Extended bandwidth with moderate rejection | Wi-Fi 6E access points |
| Narrowband Helical | Ultra-sharp roll-off and high selectivity | Satellite communication terminals |
Typical helical filters consist of: - Spiral resonator elements (copper or silver-plated) arranged in cylindrical cavities - Dielectric support structures with low loss tangent - Input/output coupling probes (capacitive or inductive) - Shielded metallic housing (aluminum or steel alloys) - Adjustment screws for frequency tuning and impedance matching The resonators operate in TE01 mode with electromagnetic coupling between adjacent helices, forming transmission zeros for enhanced selectivity.
| Parameter | Typical Range | Significance |
|---|---|---|
| Frequency Range | 0.8-18 GHz | Determines application suitability |
| Insertion Loss | 0.5-2.5 dB | Impacts signal strength |
| Bandwidth (3dB) | 0.5%-20% of Fc | Defines channel separation |
| Q-Factor | 500-1500 | Affects filter selectivity |
| Power Handling | 10-200 W | Determines system robustness |
| Manufacturer | Key Product Series | Specifications |
|---|---|---|
| Mini-Circuits | HLPS-1500+ | 0.8-6 GHz, 1.2 dB IL, 50 MHz BW |
| Analog Devices | HMC1044LC5 | 12-14 GHz, 15 W power handling |
| K&L Microwave | 6000255 | 2.4-2.5 GHz, 0.8 dB IL, 150 W |
Key selection criteria: - Required passband frequency and bandwidth - Power handling requirements (transmit vs. receive applications) - Environmental conditions (temperature range, vibration) - Mechanical size constraints - Cost vs. performance trade-offs - Regulatory compliance (RoHS, REACH) For example, in 5G small cells, compact narrowband helical filters with 3.5 GHz center frequency and 100 MHz bandwidth would be selected for their steep skirts and low phase distortion.
Current development directions include: - Millimeter-wave helical structures for 28/39 GHz 5G bands - Integration with LTCC substrates for hybrid filters - Additive manufacturing techniques for complex geometries - Enhanced thermal management materials for high-power applications - Miniaturization through fractal helix designs