ROG Blog

The Rog Blog is contributed by John Coonrod and various other experts from Rogers Corporation, providing technical advice and information about RF/microwave materials.
Glass weave

Working Through Woven Glass Weaves

Woven glass is incorporated into printed-circuit-board (PCB) materials to provide structural strength. It aids the mechanical stability of a laminate, but what does it do to its electrical behavior? One of the classic concerns regarding woven glass reinforced laminate PCBs is that the “glass weave effect” can have negative impact on the electrical performance of high-speed or high-frequency circuits fabricated on these laminates. In this blog, we examine some of the factors affecting the glass weave effect phenomenon.

Read More

Changing Temperature Can Change Circuit Performance

Circuit materials are evaluated by a number of different parameters, including dielectric constant (Dk) and dissipation factor (Df). Those two parameters also have temperature-based variants that provide insight into the expected behavior of a circuit material with changes in temperature, notably the thermal coefficient of dielectric constant (TCDk) and the thermal coefficient of dissipation factor (TCDf).

Read More

What Type of Circuit Material Works Best for Millimeter Waves?

Millimeter-wave frequencies are being used more often, in automotive radars and soon in 5G wireless networks. But before such frequencies can become widespread, low-loss circuits must be designed at frequencies such as 60 and 77 GHz, and fabricating such circuits will require suitable circuit materials. Selecting circuit materials at such high frequencies will depend upon knowing which circuit and material parameters have the most effects on performance, and finding materials with a favorable set of characteristics for millimeter-wave frequencies.  

Read More

Tracking Trends in RF Laminate Formulations

Recipes are often refined with time, in hopes of improving the results. Over the years, many different formulations have been applied to create high-frequency circuit materials. The efforts have led to a variety of current circuit laminate choices for a wide range of high-frequency applications and performance requirements.

Read More

Comparing Transmission Lines for Millimeter-Wave Circuits

Circuit designers familiar with a particular transmission-line technology may ask: Can’t I stick with microstrip at mmWave frequencies, if the PCB material delivers the performance I need?  This posting reviews the answer to this question and about how to optimize mmWave PCB designs.

Read More

People Help Turn Those Laminates into Perfect PCBs

Specifying the optimum circuit laminate for an electronic design project is often a case of reviewing the numbers. Once all these numbers have been analyzed and reviewed, the field of PCB material choices narrows until, finally, the optimum circuit material for a project can be selected. But what happens next?

Read More

Circuit Materials Keep Satcom Signals On Track

Space may be the final frontier, but the orbiting satellites that provide this planet’s satellite communications (satcom) outer infrastructure may seem even more inaccessible. In what may be one of the most hostile operating environments for electronic equipment, these satellites contain circuits that absolutely must not fail. The satcom systems in those satellites demand circuit materials capable of maintaining excellent performance and high reliability even under those stressful, in-orbit conditions.

Read More

Appreciating Advances In Circuit Materials – 100 Blogs Later

100th ROG Blog Posting

Predicting the future is never easy. Similarly, knowing which types of circuit materials will be needed for the next decade’s RF/microwave applications can be difficult to predict, but the past can provide invaluable guidance. With this being the 100th installment in this series, the previous six years of ROG Blogs provide a bit of a map for the high-frequency road ahead and what might be needed in terms of electrical and mechanical characteristics for what are expected to be large-volume applications in this industry, including in radar-based automotive electronics systems, Fifth Generation (5G) wireless communications systems, and Internet of Things (IoT) sensors almost everywhere.

Read More

Filtering Through Material Choices

High-frequency filters are increasingly essential components within wireless products, especially as those wireless products continue to compete for limited frequency spectrum. Various types of RF/microwave filters help wireless radio transmitters and receivers operate with their proper signals while shielding them interference caused by out-of-band signals. For the best results, filter designers should start with a printed-circuit-board (PCB) material having optimum characteristics for RF/microwave filters. The choice of circuit material can not only impact a filter’s performance, but even the size of a printed circuit filter.

Read More

What Happens When Circuit Material Heats Up?

Heat can be damaging. Printed circuit board (PCB) materials are formulated to withstand a certain amount of heat, but when the temperatures rise beyond certain limits, circuit performance can suffer, especially at higher frequencies. Heat-tolerant PCB materials and carefully considered circuit designs can tolerate a certain amount of heat, if a circuit designer is aware of the various parameters that best describe a circuit material’s behavior when temperatures rise. 

Read More