The waveguide, along with the coaxial line, is one of the most important transmission media in any modern RF, microwave and millimeter-wave component, and sub-assembly and system. Due to its metal tubing configuration, the waveguide tends to be heavy and bulky, especially in low microwave frequencies. However, it is always a preferred transmission means when performance and high power are priorities. In millimeter-wave bands, it is especially true that the waveguide is widely used and engineers will pay high attention to loss.
On the other hand, the coaxial transmission line offers the alternative approach. It delivers moderate RF performance, but its light and flexible features are attractive for many component and system applications. Today, coaxial components are reaching frequencies up to 110 GHz and beyond. In order to interface with various components, the standard coaxial connectors, such as SMA, 2.92 mm (K), 2.4 mm, 1.85 mm (V), 1.35 mm (E), and 1 mm are invented, fabricated and implemented in many microwave and millimeter-wave components and systems. The coaxial connector interface components are easy to use when they are integrated or interfaced with other components or assemblies. The popular coaxial connectorized components, such as amplifiers and SPDT PIN switches are displayed in Figure 1 below.
However, waveguide interfaced components are required from time to time, due to the requirements of high performance, high power handling and system integrations. Because of that, the industry is using either the coax to waveguide adapters or the dedicated package with built-in waveguide transitions to create the waveguide interface. This is shown in Figure 2 and Figure 3, respectively. A waveguide connector was never invented nor introduced to the industry since the waveguide was born 120 years ago.
The waveguide to coax adapter approach is bulky and expensive. It also introduces additional circuit loss which could degrade system performance and increase system manufacturing cost. On the other hand, the dedicated package with built-in waveguide transition option requires special or custom designs and manufacturing process, which is costly and time consuming. Furthermore, this option is not flexible and creates additional parts to manage, which is not welcome in any manufacturing organization.
It would be desirable if the waveguide connector, like the coaxial connector, existed so that the direct waveguide interface can be realized without additional engineering efforts, extended development cycle time, and massive inventory management. In addition, hermetically sealing the waveguide involves a special and costly process. SAGE Millimeter has invented the waveguide connector to overcome these difficulties. Figure 4 shows the newly invented, patent pending and trademarked waveguide connectors. Currently, SAGE Millimeter has released WR-28, WR-22 and WR-19 waveguide connectors to accept the most commonly used 12-mil diameter glass bead with 0.48” mounting hole separation in the industry. Other bands and configurations are still under development.
From Figure 5, one can see how the direct replacement of the coaxial connector to form the waveguide interface is accomplished.
In addition, the newly invented waveguide connector offers flexible installation to form various waveguide orientations. While Figure 6 shows that the input and output waveguide ports are vertically aligned, Figure 7 shows they can be horizontally aligned just by rotating the connectors 90-degrees. Furthermore, the input and output waveguide port can be aligned orthogonally by simply turning one port 90-degrees relative to the other port, either the input or output port depending upon the customer’s applications.
As mentioned earlier, the waveguide connector solves the hermeticity challenges with no efforts and no additional cost. This is simply because it is a connector just like the coax connector. Once the package is sealed, there is no need to seal the waveguide window.
Furthermore, the waveguide connector can reduce product development cycle time, eliminate additional design cost and minimize additional inventory management. Instead of developing various custom waveguide interfaced packages to satisfy different frequency bands and waveguide orientation requirements, only a few standard housings and waveguide connectors are needed to accommodate many package variations.
As a by-product, the newly invented waveguide connector can be formed into a compact waveguide twist by connecting two units back to back. It can be set as a default 90-degree twist with the standard design. With minor mechanical updates, it can form a universal twist with arbitrary angles. The twist illustration is shown in Figure 8. The trademark for the waveguide connectors is Uni-Guide™, which can play equal and more extended roles in any microwave and millimeter-wave components and sub-assembly interconnections as coaxial connectors.
Currently, SAGE Millimeter is focusing on developing the WR-42, WR-15, WR-12 and WR-10 Uni-Guide™. SAGE Millimeter also accepts custom inquires to develop custom waveguide connectors to satisfy various waveguide interface requirements. Send your request to email@example.com or visit our Contact Us page and we will be happy to get back to you.
*Trademarked and Patent Pending