Mobile Communication / DECT

DECT: Technology and Filter Requirements

DECT (Digital Enhanced Cordless Telecommunications) is a globally established standard for cordless voice and data proximity communication, primarily operating in the dedicated frequency range of 1,880 MHz to 1,900 MHz (Europe). In other regions, such as the USA, the technology is utilized as DECT 6.0 in the range of 1,920 MHz to 1,930 MHz. Technologically, DECT is based on a combined TDMA/FDMA method, enabling high user density and excellent voice quality through dedicated frequency reservation. The greatest challenge for RF hardware today lies in the immediate proximity to high-power cellular services such as LTE Band 1 (2100 MHz) and emerging 5G services, which can overload high-sensitivity DECT receivers. Wainwright Instruments provides specialized high-performance filters for these demanding infrastructures, designed to precisely isolate the narrowband DECT spectrum from broadband cellular interference. As modern DECT systems are increasingly used for industrial IoT applications (DECT NR+), extreme skirt steepness is required to ensure link reliability in spectrally burdened environments. Our filter solutions protect receiver front-ends from saturation and guarantee crystal-clear voice transmission and error-free data streams, even when base stations are installed in close proximity to cellular towers.

Typical Deployment Scenarios:

DECT filters from Wainwright are crucial components in systems requiring absolute reliability and maximum signal purity in business-critical communication environments.

Enterprise Communication Systems: In large office complexes, our filters secure the connection between base stations and handsets against radiation from the internal LTE/5G network.
Hospital Communication: In clinics, our filter solutions ensure interference-free alerting and voice transmission for medical staff by isolating DECT signals from neighboring medical radio devices.
Industrial IP-DECT Networks: Within manufacturing plants, our RF components protect the infrastructure from electromagnetic interference from machinery parks, enabling uninterrupted control of logistics processes.
DECT NR+ for IoT: For modern smart city applications and industrial sensor networks, our filters secure the signal quality of the new 5G-based DECT generation in the 1.9 GHz range.
Public Safety Authorities: In control centers and security hubs, our filter solutions prevent the blocking of radio paths by neighboring commercial cellular transmitters at shared antenna sites.
Event & Conference Technology: For wireless intercom systems at large-scale events, we provide filters that stabilize signal purity in environments with extremely high radio density and numerous parallel wireless applications.
Test and Certification Laboratories: For validating the interference immunity of new DECT components, we supply high-precision reference filters to characterize receiver performance under controlled conditions.
Home Networking & Smart Home: In gateway systems, our robust filters protect the DECT interface from overloading by the integrated high-power transmitters for Wi-Fi 6/7.

Suitable Filter Categories for Wireless Connectivity & IoT / DECT

The narrowband nature of the DECT spectrum in close proximity to broadband services demands filter solutions with extraordinary selectivity and thermal stability.

Band Pass Filters

Our DECT Band Pass filters enable precise selection of the frequency range from 1,880 MHz to 1,930 MHz. They are specifically optimized for use in professional base stations (Fixed Parts) and industrial infrastructure applications, combining steep rejection skirts with minimal insertion loss. This maximizes the range of handsets and protects receivers from saturation by strong neighboring signals from the LTE Band 3 (1,800 MHz) or UMTS/LTE Band 1 (2,100 MHz) range. By using high-quality resonators, we ensure that spectral purity is maintained even at high user densities, significantly improving Quality of Service (QoS). Manufacturers of infrastructure components benefit from the high power handling and selectivity of our filters.

Manually Tunable Band Pass Filters

For the development of DECT hardware in laboratory environments, we offer manually tunable Band Pass filters covering the range from 1.8 GHz to 2.0 GHz. Via high-precision mechanical tuning elements, the center frequency can be adjusted exactly to regional DECT frequency plans or specific channels for investigating edge interference. This flexibility allows engineers to investigate the robustness of their designs against targeted cellular interference in the lab. The robust construction of our manually tunable filters guarantees permanent reproducibility of the filter curve for consistent measurement results.

Digitally Tunable Band Pass Filters

Electronically controllable filters support modern SDR-based DECT architectures and automated test environments that must react agilely to various global frequency plans. Via digital interfaces such as SPI or I2C, filter parameters can be adjusted in real-time, which is particularly advantageous for automated test sequences checking channel selectivity. Our digitally tunable filters combine digital control precision with the necessary RF quality and are optimized for use in test environments and development systems. They enable rapid reconfiguration of test scenarios without manual hardware swaps.

Band Reject Filters / Notch Filters

Our DECT notch filters serve to eliminate specific interfering signals located immediately adjacent to the utilized DECT spectrum, such as strong LTE signals. They feature extremely deep stopband attenuation while the rest of the DECT passband remains nearly unaffected. This protection is fundamental to prevent saturation of receivers in base stations at sites with high cellular density. By using our notch filters, the robustness of the infrastructure against narrowband interferers is massively increased, significantly increasing the reliability of communication in urban metropolitan areas.

Manually Tunable Band Reject Filters / Notch Filters

Frequency-tunable notch filters provide a flexible solution for interference suppression directly in the field during the commissioning of enterprise DECT systems. By manually adjusting the stopband frequency, interfering signals caused, for example, by neighboring cellular repeaters can be masked immediately. This ensures the availability of communication services without waiting for new filter hardware. The mechanical precision of our filters guarantees that once a stopband frequency is found, it remains stable, which is particularly decisive for permanently installed base stations on facades or masts.

Digitally Tunable Band Reject Filters / Notch Filters

In intelligent communication networks, digitally tunable notch filters enable an automated response to dynamic interference scenarios. Controlled by monitoring algorithms, these filters can dynamically mask interfering signals in real-time to maintain Quality of Service for critical applications such as industrial emergency systems. Their integration into automation concepts for radio optimization allows for autonomous radio optimization of entire corporate areas. Thanks to remote controllability, operators can adjust filter characteristics centrally, reducing operating costs and massively increasing resilience against new interference sources at shared mounting locations.

Monoplexer / Diplexer / Duplexer / Triplexer

Separating transmit and receive paths at a DECT base station requires high-performance duplexers with high isolation to prevent mutual blocking of the high-sensitivity receiver paths. Our solutions for the 1.9 GHz band are optimized for highest power handling combined with minimal PIM (Passive Intermodulation). Triplexer solutions are used when DECT must be combined with other services such as Wi-Fi or LTE on a shared antenna. Wainwright Instruments manufactures these components with the highest precision to ensure that multi-mode gateways develop their full performance. Our multiplexers are optimized for use in professional communication systems and industrial infrastructure applications.

Absorptive Filters

Absorptive filters play a crucial role in the transmission infrastructure of high-performance DECT repeaters to preserve carrier signal purity. Rather than conducting unwanted harmonics or reflections back to the power amplifier, these filters safely convert them into heat, preventing signal distortion in the TDMA time slot. This is particularly important for complying with strict regulatory emission standards in environments with many parallel radio systems. Our absorptive filters are designed for continuous operation and increase communication precision by consistently minimizing thermal stress and signal reflections.