Christopher F. Marki received his B.S.E.E. from Duke University in 2002 and his M.S.E.E. and Ph.D. from University of California, San Diego in 2004 and 2007, respectively. While in graduate school, Christopher studied high speed fiber optics and consulted for San Diego start-up Ziva Corporation. Following graduate school, Christopher decided to forego a life in Photonics and opted, instead, to work with his father at Marki Microwave and learn the “family business” of microwave mixers. While at Marki Microwave, Christopher has served as Director of Research and has been responsible for the design and commercialization of many of Marki’s fastest growing product lines including filters, couplers and power dividers. Dr. Marki has authored and co-authored numerous journal and conference publications and frequently serves as an IEEE reviewer for Photonics Technology Letters and Journal of Lightwave Technology. MarkiMicrowave.com
To comment or ask Christopher a question, use the comment link at the bottom of the entry.
When people ask my advice about pursuing a career in Engineering, I tell them the following:
If you can go 30 days of the month without good news or good results, only to find on the 31st day that your project works perfectly, and this good news puts you in such a euphoric mood that you can forget about all the previous frustrations, then you are going to be a great engineer. If that sense of personal accomplishment isn’t good enough to make you happy, then you should consider doing something else.
Today is the 31st day of my month, and I am happy to share with you some good news, both about some of our newest products, and about the fact that Marki Microwave is looking to hire some ambitious and talented new employees. (I promised myself I wouldn’t use this blog as a platform to advertise Marki Microwave explicitly, but sometimes I just want to talk about some of our newest designs, especially when they’ve been in the development pipeline for so long.)
For quite some time, I have been trying design Wilkinson power dividers with (nearly) unlimited bandwidth. I didn’t really have a customer requirement forcing me to do so, but I was looking for a complementary power divider line to our popular broadband directional couplers and 3 dB quadrature hybrids. The challenge has always been twofold: I wanted to avoid using multi-layer stripline geometries to make the power dividers, and I wanted a way to make them work well beyond 26 GHz. Avoiding stripline would make the part cheaper to build by reducing complexity and assembly time, and making power dividers above 26 GHz would enable me to meet higher frequency requirements to 65 GHz.
I am happy to announce that after our metaphorical 30 days of hardship in lab and 3D computer simulation, we now have a design technique that enables us to build power dividers from below 400 MHz to 65 GHz. These new power dividers are based on a novel approach to making Wilkinson power dividers that eliminates the costly stripline assembly while also minimizing the deleterious effects of line discontinuities in conventional multi-section Wilkinson designs. The first released power dividers using this new construction offer bandwidth ratios of approximately 40:1 including the PD-0R413 (400 MHz to 13 GHz), the PD-0R618 (600 MHz to 18 GHz) and the PD-0140 (1 GHz to 40 GHz). Typical isolations exceed 20 dB with outstanding amplitude and phase balance. It is important to point out that these designs are totally symmetric between the output ports meaning that the overall balance of the circuits is superior to other vendors’ solutions that employ asymmetries which severely limit the performance at higher frequencies. In the coming weeks, we will be announcing additional power dividers which can cover 65:1 bandwidth. If you would like to be kept up to speed on these and related product releases, please sign up for Marki Microwave’s monthly newsletter by clicking here.
As I mentioned above, I am also excited to announce that Marki Microwave is hiring. We are currently looking to fill an opening for a Technical Marketing Engineer. This role requires someone with some engineering background but wants also can excel in a Sales/Marketing position. If you, or someone you know has this skill set and is looking for employment, please send a resume to firstname.lastname@example.org.