Microwave Journal
www.microwavejournal.com/articles/22827-executive-interview-with-bob-alman

Executive Interview with Bob Alman

Off-the-shelf High Performance Switching Solutions

August 14, 2014

MWJ: Can you give us a little background and history on SenarioTek for those not familiar with your company?

BA: Located in Santa Rosa, California, SenarioTek, LLC was formed on Jan 2, 2004, comprised of engineers, technicians, assemblers and procurement folks whose jobs had been outsourced from Santa Rosa to Malaysia.  The focus of the business was to provide high performance custom switching and signal conditioning products at an affordable price.

MWJ: What do you see as the major growth markets/opportunities for SenarioTek in the near term?

BA: High speed serial test is a growing opportunity.  As the data rates of high speed serial connections continues to rise, signal integrity becomes very challenging to measure.  SenarioTek has developed many multi-lane switching products to test differential signals up to 40 GHz.  The challenges are minimizing insertion loss, and matching the signal paths to preserve the balanced measurement.   Delay matching is an area we have put a lot of effort, including cable selection, thermal processing of cables for long-term stability and most importantly, ensuring that the repeatability of the measurements from cycle to cycle is as good as possible.   As the data rates rise, and the bandwidths get into millimeter wave frequencies, the margins for repeatability get tighter, and the need to match the characteristics of each of the differential paths becomes more important and harder to attain.  SenarioTek has been supplying switching systems like this since 2005 and has focused on optimizing the performance of the switch matrix to minimize the errors in the measurements.

MWJ:  What range of solutions do you provide - frequency ranges, switching speeds, switch types, etc.?

BA: Our standard products range from DC to 40 GHz and are based on electromechanical switches.  The switching topologies of the standard switches cover the common types of common highway, full-access blocking, and differential configurations.  We have a number of standard configurations listed in our brochure, but there are nearly infinite numbers of configurations available that would require no NRE.   The listing becomes an issue of practicality.

Our custom offering includes all types of switching and signal conditioning capabilities that include electromechanical, and various types of solid state solutions that use PIN diode, FET, SOI, and some lightwave capabilities.   Frequency ranges go up to 67 GHz using our in-house testing. 

MWJ: What differentiates your switching solutions from others?

BA: I think the main differentiator is that this is the only thing we do.  Our products are not a vehicle to sell other products we build, but are the end use product.  This means that instead of incorporating parts that we build, we use our expertise to select the best components available like switches, cables, connectors, etc., and use them to build the switching and signal conditioning products we offer.  We work with vendors to improve their products to suit our needs.

MWJ: SenarioTek has traditionally been a high performance custom RF switching company – how did you make the decision to add standard products to your portfolio?

BA: That's a very good question.   From day one, we set out to produce high performance, cost effective solutions, tailoring each solution to the customer's specific needs.   We always felt that a small company is best suited to address the needs of custom products, allowing us to become an extension of our customer's design team.

The issue we faced was that we almost started from scratch with every new design, particularly where it comes to power and control.  We set out to design modular building blocks to reduce our effort to produce one-off products.  After we accomplished this, it became obvious that we could offer a family of flexible standard products that took advantage of the years of custom, high performance designs.  We used innovation, offering cable management brackets and remote LCD control to reduce the size of the switch matrix, but retain the convenience of manual control/display.   The result is a high performance flexible family of switching products that are easily customizable with little or no NRE in most cases.

Most companies go from standard to custom; we did it backwards.  The advantage is that the high performance techniques that have been developed in tough, custom designs have been leveraged into our standard products.

MWJ: How does the standard product ordering and specification process work?

BA: The easiest way to figure out what is needed and then order it is to visit our website and download the FlexMatrix brochure.   It has sections that describe the various configurations and the tradeoffs.  After a switch matrix type is chosen, there is a link to request a quote and fill out a few fields and send off the request to SenarioTek.   SenarioTek will contact the sender and refine the request to ensure the choice is really what was needed.  Often, SenarioTek can help customers with the matrix choice and often save money by using a less expensive design, or avoid a buy decision that may not work the way the customer expects.  A good example is whether self-terminating inputs or outputs are needed.  Often terminated options are selected to be safe, but we can help determine if they are actually required.  Savings can be significant either way!

MWJ: SenarioTek has special expertise in thermal vacuum switching solutions – how did you get into that business and tell us a little about the requirements for such a solution?

BA: Thermal vacuum applications require attention to a lot of details and demand the highest performance and reliability available.   We often try to repeal laws of physics to attain the goals the customer wants!

The special requirements are first to ensure there is no outgassing or prohibited materials present in the products that go inside the vacuum chamber with the satellite.   Contaminating a satellite or the vacuum chamber is extremely expensive!  The second part of the difficulty is that the vacuum testing can last a month or two and can cost hundreds of thousands of dollars per day.   Anything that goes inside the vacuum chamber MUST be super reliable.   A failure in thermal vacuum could cost a million dollars or more.   Late delivery of a satellite can cost the customer as much as $8 million dollars per day.  Missing a launch can bankrupt the end customer.   It's a very demanding requirement.

The other aspect is creating hardware that enables the customer to make accurate, repeatable measurements in difficult conditions.  Often, the satellite is 50 or 60 feet away from the test rack, and the test requirements demand accuracy on the order of +/- 0.25 dB at Ka band frequencies over periods of weeks or months.   Techniques that we have developed have enabled our customers to monitor power and make error correction on the fly.  Super repeatable switching networks minimize errors that cannot be calibrated out.   Accuracy and precision rule the roost.

MWJ: You specialize in high reliability solutions – how do you ensure that your systems perform well over time?

BA: Reliability and repeatability go hand in hand in our designs.   Experience in component design gives our engineering team the ability to examine and evaluate components like switches, cables and connectors to select the ones that ensure the highest performance and reliability.   Electromechanical switches are the Achilles heel of most switching systems and demand the most attention.   In my previous job, I spent over 15 years designing and evaluating electromechanical microwave switches, both my designs and those of the competitors.  The majority of electromechanical switches do not provide the level of performance or reliability suitable for use in SenarioTek products.  Few have the necessary reliability, and almost none have the required repeatability.   I found that reliability and repeatability are not scalable; there is a threshold that separates unreliable and unrepeatable products in a dramatic way.

The components (mainly switches, cables and connectors) that meet the requirements for use in SenarioTek products must satisfy the following criteria:

1.  The inherent design must support the ability to provide high reliability.
2.  The vendor must have an ongoing program that sample tests the quality and long-term reliability
3.  The components perform well in SenarioTek's reliability evaluation (life testing, repeatability monitoring, and field failure incidents)

The result of this work has produced products with near zero field failures over a 10 year span.  The attention to design, performance monitoring, and working closely with suppliers pays off with highly reliable products.

What geographic areas offer the best growth opportunities for SenarioTek and why?
Most geographic areas present great growth potential for SenarioTek.  Our products span such a wide variety of applications that areas with high concentrations of particular business needs are just as likely to benefit from our product offering:   Flexible, high performance, high reliable, cost effective switching and signal conditioning products.

MWJ: What are your major long term goals and where do you see the company heading in the future?

 BA: I look forward to see the company provide innovative, flexible solutions to a wide customer base who needs affordable high performance, reliable switching products.