Modern Trends in Microwave Passive Components

With increased frequencies, higher data rates, and lower noise levels, the microwave industry serves as a leader in technological capability. Component General, Inc. (CGI) plays a strong role in providing advanced microwave components.  CGI has application expertise in test and measurement, component simulation, Radar applications, wireless communications, industrial, scientific, medical applications and homeland security applications. CGI is focused on your needs via standard off the shelf catalog items, custom versions of standard products, custom designs for specific applications and prototyping. CGI delivers more than 100 catalog items, some “in stock” inventory with specials delivered within 4 weeks. We have in house measurement capability from DC to 40 GHz. We have a MIL-I-45208 quality assurance program and a  MIL-STD-45662/ANSI/NCSL Z540-1-1994 calibration program. We have in house CNC machine shop capability. We can provide complete documentation to include electrical, mechanical and test data.

Component General manufacturers its products wholly in the USA with most all raw materials coming from the USA as well. This philosophy puts Component General into the position of being self-sufficient. Self-sufficiency provides the ability to fully control quality and delivery times since they are set by the day to day processes and not so dependent on outside vendor product deliveries. Component General uses modern manufacturing methods including laser trimming, dicing, and scribing. CGI also has robotic workstations for the automation of repetitive assembly procedures. 

Standard processing methods for our manufacturing of “thick film” products include screen printing of thick films and most recently, masking procedures for the production of “thin film” products. While these methods are well established procedures, they are still very viable in today’s technology. The next generation of component manufacturing will likely encompass the use of 3-D printing techniques. This new and uprising technology will certainly add precision and speed to the manufacturing process. The 3-D tools are advancing steadily and will provide total computer control of the resistor and termination geometries. The conductors for these products will likely be composed of silver nanoparticle ink that can be accurately printed via computer control. 3-D printing techniques using a combination of laser sintering and nanoparticle deposition will become a $2 Billion dollar market by 2015.  Looking forward, CGI intends to utilize this technology as it becomes available.

Key to anticipated new business, CGI has ventured into the manufacturing of a complete aluminum nitride product line. These products currently include microwave terminations and resistors. Our web site (www.componentgeneral.com ) currently lists some of the new products available with more being added each week. Currently there are four types of ceramic materials used to make terminations, attenuators, and resistors. They are aluminum oxide, aluminum nitride, beryllium oxide, and CVD diamond. This list is given in the order of heat handling capability with CVD diamond being the best heat capacity material.   Aluminum nitride ceramic is preferred worldwide since it is very environmentally friendly. However, it does not have the heat capacity of beryllium oxide.

CGI intends to also offer a full product line of thin film products encompassing terminations, attenuators and resistors. There are some distinct advantages in using thin film. Specifically, this manufacturing method allows for great precision, smaller product size, repeatability, high reliability, and increased power density in some cases. Both nichrome and tantalum nitride resistors will be employed. TaN resistors are self passivating and resistant to moisture problems.  CGI has full “in house” capabilities to produce thin film products.

It would seem prudent to mention that technology is constantly pushing component sizes to smaller and smaller geometries. The largest problem to overcome is the removal of heat within the terminations, attenuators, and resistors. This is accomplished by keeping the thermal resistance very low for all the stackable elements of the design. So, the choice of ceramic material is critically important from the standpoint of heat transfer. The dielectric constant is critical from a design viewpoint.

Correspondingly, the “frequency of use” is also increasing with medium sized power chips.  Broadband requirements are now 4 GHz. or greater for these chips.  Component General has measurement and construction capabilities to 40 GHz. In order to achieve this broadband capability, it is necessary to have accurate compensation networks within the chip design where the equivalent circuit can be “tuned” to the desired range of operation. CGI has the necessary computer software to simulate and analyze these advanced designs. Design is accomplished using Sonnet and the Microwave Office line of design tools. Measurement of desired parameters is accomplished using a Anritsu 40 GHz network analyzer.

Included in CGI’s capabilities is the ability to make high voltage serpentine resistors with temperature coefficients of 50 ppm/ Degree C with 100 ppm/Degree C being standard. CGI can also manufacture laser trimmed serpentine style heaters used by the optical industry. These heaters are used to heat stabilize optical waveguides.

CGI’s higher power coaxial products support a large number of input/output style connectors including SMA, N. BNC, TNC, EIA Dins 1 5/8 and other European styles when needed.

New engineering materials are emerging every day that allow component performance enhancement. One of these materials recently introduced by Times Microwave is the TF4 dielectric. It has substituted for PTFE (Teflon) and has eliminated the non-linear phase performance in the 15-25 Degree C  temperature range that has been for so long a detriment of PTFE material.

Looking ahead still further, for those of us engaged in R&D design of next generation products, millimeter wave devices are rapidly gaining favor. Millimeter waves (30-300 GHz) are a subset of the microwave band and are utilized to deliver pencil-beam thin, high bandwidth, wireless communications at speeds that rival fiber optics WITHOUT the associated latency issues.  Millimeter wave technology is also being applied to the next generation of radar systems buoyed by quantum leaps in digital processing bandwidth and processing speed. CGI intends to be a part of these exciting advances.

Some of the largest trends in the microwave industry, as we see it, would be in the following areas:

  1. Gallium Nitride: A dominant technology for high-frequency applications where one can take advantage of the wide bandgap and low output capacitance of GaN devices.
  2. Tunable systems: Tunable matching will be critical to new defense systems.
  3. Bio-medical applications:  Sensing, imaging, and wireless healthcare.
  4. Wireless power transmission and power harvesting: Wireless charging of batteries and implanted device.

From above, one can see an exciting future for microwave product developers. CGI is poised and ready to accept the challenge.

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