Electrical Engineering & Mathematics — Sonoma State University. I build and measure things across the stack: RF/microwave circuits, semiconductor fabrication process flow, and embedded hardware systems — then I put them on a network analyzer to see how wrong I was.
Remote Energy Access and Control Hub
An external hardware module built for EE 493 Senior Design at Sonoma State University, developed with Husch Vineyards as the client. R.E.A.C.H. bolts onto existing remote solar power systems to add power management, LTE-based remote monitoring, outlet-level scheduling, and load prioritization for field devices in vineyards, ranches, and other rural sites — with a Grafana cloud dashboard and an on-device E-Ink display for real-time status.
Team: Jair Pacheco, Kamryn Shigemoto, Juan Jimenez — advised by Dr. Farid Farahmand (SSU) and Mr. Noah Mervine. Juan's role: physical construction of the device, and measurement / data acquisition feeding the project's telemetry database.
↗ VIEW FULL PROJECT SITEThree microstrip circuits designed in Keysight ADS, then hand-built on cardboard and FR4 with copper tape, and measured on a Keysight FieldFox network analyzer at a 433 MHz design frequency.
Two quarter-wave 70.7 Ω branches plus a 100 Ω isolation resistor, built on FR4 substrate with copper tape in a symmetric circular layout to keep both output legs electrically matched.
| Return loss (S11) | −23.02 dB |
| Insertion (S21 / S31) | −2.78 / −2.84 dB |
| Isolation (S23) | −22.93 dB |
All three specs (>10 dB return loss, >15 dB isolation, ~−3 dB split) met at 433 MHz.
A BFP520-style LNA topology re-tuned for a BFP420 transistor after a supplier substitution, run off a 3.3 V rail. Designed and simulated in ADS, laid out in KiCad, then hand-soldered and measured.
| Simulated gain (S21) | 15.36 dB |
| Measured gain @433 MHz | 14.20 dB |
| Measured gain @center freq | 17.79 dB |
Build shifted center frequency to 359 MHz — a lesson in trace geometry and connector loss.
A 5th-order L-C-L-C-L lumped-element filter, simulated with ADS LineCalc against a measured cardboard "substrate" (εr=2.5), then realized as alternating wide/narrow copper-tape sections.
| Simulated S21 @432.8 MHz | −3.08 dB |
| Measured S21 @433 MHz | −2.79 dB |
| Measured S21 @866 MHz | −11.94 dB |
One octave up, attenuation nearly quadrupled — filter behaved as designed.
Physical Electronics — Final Project
A full front-end-of-line process flow for the classic 741 operational amplifier, covering Si-MOSFET fabrication, thin-film capacitor fabrication, and TaN thin-film resistor fabrication, then integrating all three device types into one process to realize the 4-stage 741 architecture (input, gain, level-shift, output).
Group project with Zella Waltman and Kevin Perry.
Source, firmware, and write-ups beyond what's staged here — including code from R.E.A.C.H. and other coursework.