Accelerating Innovation in RF Applications with Smaller & Lighter RF Filters

Benchmark Lark Technology, a leading expert in RF and high-performance circuit design and fabrication, has introduced new filter product lines that are designed to give RF engineers new options to address size, weight, and power (SWaP) temperature tolerance and integration into designs through the ability to effectively stack, embed and surface mount components.

Benchmark Lark Technology combined its 30 years of experience in the RF components space with advanced circuit manufacturing technology to develop a new line of customizable bandpass, bandpass, highpass, and lowpass filters using LCP material for frequencies up to 40 GHz. Essentially, these are traditional stripline filter designs made using a proprietary circuit fab process with LCP.

This filter design allows engineers to customize small, wideband and high-performance filters using the fine lines and spaces (currently at 25 microns) that are not achievable using conventional circuit fab techniques. The overall package is planar and extremely thin, making it ideal for surface mounting or stacking.

Design Options are Expanded When Filters Can be Stacked

While small filter size is a huge advantage on its own, being able to stack-up multiple filters further reduces the area required for board layouts in any RF system. It also eliminates the need for interconnects since components are installed using an SMT process. Customers have been asking for stacked filters as it gives them the ability to integrate more functionality into their RF board layouts. Benchmark is also working on incorporating active functions into a custom surface mountable solution including switches, mixers, and amplifiers.

At the end of the day, it is all about the SWaP. Stacking filters gives customers the ability to make a significant reduction in size and weight and allows them to get more functionality in a smaller footprint. There is no compromise on performance since these filters still perform comparably to other technologies that are much larger, i.e. cavity or lumped element filters. This capability can be applied to just about any application requiring filtering, switching or amplification including RF front-end phased array receivers for UAVs, CubeSats, and airborne radars / EW systems.

Applications of Smaller, Lighter Filters

The new design possibilities offered by thin, stackable stripline filters, or filter integrated solutions, are starting to have an impact in a number of applications. A few examples include:

UAVs: UAVs are becoming smaller and smaller, so the electronics used for data links, control, and intelligence gathering need to be smaller and lighter as well. Typical sizes are 3 X 5 inches for the entire radio system. Benchmark's LCP filters are ideal for these applications due to their small footprint and light weight.

Airborne Radar/Electronic Warfare: For systems contained in an external pod, customers are constantly fighting SWaP due to increased power requirements. Benchmark's small form factor filters allow them to get multiple receiver channels in a typical 3U (4X6 inch) chassis, allowing them to gather even more data in the same footprint. More data means more signals gathered for intelligence analysis, more data to use for signal jamming, and more dynamic range on radar front-end receivers. Due to the inherent accuracy of circuit fab process, the LCP filters also have a tightly matched phase and amplitude response that is critical for most radar systems.

Satellites (CubeSats and Others): Anything that goes into space needs to be not only radiation-tolerant, which LCP is, but also lightweight since any added mass requires more power to keep the satellite in orbit in addition to the power for all the electronics that keep it functioning. The greater the mass, the greater the power that is required and, therefore, the greater the number of solar panels. This drives the overall size of the payload and launch vehicle. LCP filters reduce the mass and significantly miniaturize the size of the radio package allowing for redundancy on a smaller payload size that can be carried by smaller, easier-to-launch satellites.

Filters are Only Part of the Story

Beyond the very small filters themselves, the same circuit fabrication technology that allowed Benchmark to build the LCP stripline filters is solving problems in RF circuit design. The ability to create fine lines and spaces in upwards of 10 layers in a low-loss, low-dissipation factor material such as LCP offers new circuit densification options. Also, the circuit fabrication process and material set are optimal for embedding RF components within a board stack up, an excellent solution for many SWaP challenges across applications.

One great example of this technology in action is embedded RF components in 5G wireless infrastructure, such as antenna arrays and switches. In the most advanced RF designs, RF system engineers are opting to mix materials in order to combine RF and compute functions without interference using 3-Dimensional Heterogeneous Integrated Circuits (3DHI).

This can reduce latency and potential points of failure by eliminating connection points. Engineers in defense and aerospace applications with no tolerance for latency and high-reliability requirements are pioneering this technology, which offers significant potential benefits in many RF applications.

Click here to see this detailed post on the Benchmark Lark Website.