The Opportunities and Challenges of LTE Unlicensed in 5 GHz
David Witkowski, Executive Director, Wireless Communications Initiative
In 1998, the Federal Communications Commission established the Unlicensed National Information Infrastructure or U-NII 5 GHz bands. These are used primarily for Wi-Fi networks in homes, offices, hotels, airports, and other public spaces and also consumer devices. U-NII is also used by wireless Internet Service Providers, linking public safety radio sites, and for monitoring and critical infrastructure such as gas/oil pipelines.

MMD March 2014

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Band Reject Filter Series
Higher frequency band reject (notch) filters are designed to operate over the frequency range of .01 to 28 GHz. These filters are characterized by having the reverse properties of band pass filters and are offered in multiple topologies. Available in compact sizes.
RLC Electronics

SP6T RF Switch
JSW6-33DR+ is a medium power reflective SP6T RF switch, with reflective short on output ports in the off condition. Made using Silicon-on-Insulator process, it has very high IP3, a built-in CMOS driver and negative voltage generator.

Group Delay Equalized Bandpass Filter
Part number 2903 is a group delayed equalized elliptic type bandpass filter that has a typical 1 dB bandwidth of 94 MHz and a typical 60 dB bandwidth of 171 MHz. Insertion loss is <2 dB and group delay variation from 110 to 170 MHz is <3nsec.
KR Electronics

Absorptive Low Pass Filter
Model AF9350 is a UHF, low pass filter that covers the 10 to 500 MHz band and has an average power rating of 400W CW. It incurs a rejection of 45 dB minimum at the 750 to 3000 MHz band, and power rating of 25W CW from 501 to 5000 MHz.

LTE Band 14 Ceramic Duplexer
This high performance LTE ceramic duplexer was designed and built for use in public safety communication and commercial cellular applications. It operates in Band 14 and offers low insertion loss and high isolation to enable clear communications in the LTE network.
Networks International

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October 2013

Marki Microwave Combines Microwave Office with Microlithic Manufacturing for Successful Custom Mixer Designs

Marki Microwave has a multi-decade legacy developing industry-leading, high performance components, including broadband, low conversion loss, and highly linear mixers, high directivity, low return loss couplers and directional bridges, well balanced power dividers and hybrid couplers, and many other quality products.  The company’s goal is to invent technologies that empower the RF and microwave industry to design faster, simplify production, eliminate complexity, and shatter performance barriers. This goal is achieved through intensive research, product development, and advanced and carefully controlled production.

Figure 1: Marki Microwave’s Ferenc Marki, President (left) and Christopher Marki, Director of Operations and inventor of the Microlithic process (right)

The Design Challenge
Marki Microwave was using a very time-consuming, empirical design process to produce the highest quality mixers for customers who expect the best performance available in the smallest footprint. As with all labor-intensive manufacturing, scaling towards higher volumes was a challenge, and, in addition, it was difficult to develop next-generation mixer designs that were compact enough to fit into shrinking footprints. Despite the industry-leading performance of their mixers, Marki had reached the fundamental limit on how small a mixer could be built by hand, but knew that it must overcome these challenges in order to continue to innovate and advance the technology of its mixers for the future.

The Solution
Marki developed a revolutionary new mixer design and manufacturing flow that leverages AWR’s Microwave Office circuit simulation software combined with Marki’s patent-pending Microlithic mixer manufacturing process in order to achieve more compact mixers with the same top quality and performance as their current hand-crafted ones.

Figure 2: Marki Microwave high performance mixer

Marki Microwave implemented a complex design cycle. First, passive structure models were created using conventional techniques. Next, these structures were integrated with nonlinear diode models and simulated using the Microwave Office® APLAC® harmonic balance simulator. Through careful control of the model parameters, these models were refined until the targeted results were produced, which were used to refine the passive structures. When units were finally fabricated, the simulation results were accurate enough to pinpoint and troubleshoot test problems. Lastly, measurement data was used to refine the model parameters before release of the models to Marki’s customers.

Figures 3 (top) and 4 (bottom): Microwave Office delivered exceptionally good simulated results versus measured performance of Marki’s Microlithic mixer.

Thanks to the Microlithic/Microwave Office process, Marki has achieved a 14x reduction in size and a 5x reduction in design time while at the same time delivering the highest performance in the industry and scalable manufacturing. An additional benefit of the new Marki design process is the ability to provide its customers with an AWR behavioral model. This enables customers to design Marki Microwave world-class mixers into their end circuits, systems, and subassemblies and harness the same power and advantages of a simulation-driven design methodology that Marki has found so enabling.

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Uncertain Times for DefenseWill OpenRFM Shake Up the Microwave Industry?
By Barry Manz

Throughout the history of the RF and microwave industry there has never been a form factor standardizing the electromechanical, software, control plane, and thermal interfaces used by integrated microwave assemblies (IMAs) employed in defense systems. Rather, every system has been built to meet the requirements of a specific system, which may be but probably isn’t compatible with any other system. It’s simply the way the industry has always responded to requests from subcontractors that in turn must meet the physical, electrical, and RF requirements of prime contractors. Read More...

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