Junior Radio Frequency Engineer Jobs in Puerto Rico

Everything the detection stack can hear is bounded by what the antenna captures and what the front end preserves. You own that boundary, from the air interface to the samples the SDR hands off. You also own the measurement function that proves it works. You will report to the CTO.

• Antenna fabrication and measurement. Our antennas are designed in house. You build what the design calls for and you prove what it actually does. Sheet metal, 3D-printed structures, RF PCB, connectors, and phase-matched cabling. VNA measurement of S11, return loss, and bandwidth. Gain and pattern measurement, in a chamber or by open-field comparison. Tolerances matter here: on a direction-finding array, a feed path a centimeter long is a bearing error in the field. You report the pattern you measured, not the pattern that was simulated.
• RF front end. Filtering, LNA and gain distribution, sensitivity and noise figure, IP3 and dynamic range, intermodulation and blocker rejection, cabling and connector loss budgets. You own the tradeoff between hearing the weak signal and surviving the strong one.
• Waveform analysis. Characterize UAS control link and video downlink signals from raw IQ. Modulation, bandwidth, symbol rate, hopping behavior, framing. You tell the detection engineer what is actually in the air.
• Test bench and procedure. Instrumentation, calibration, controlled signal injection, repeatable written procedure. If a result cannot be reproduced next month, it is not a result.
• Over-the-air collection. Live Group 1-3 targets across wooded, open, and urban terrain. Fixed and moving. Multiple airframes, including modified ones.
• Ground truth and dataset hygiene. Labeling protocol, versioning, metadata discipline. The training corpus is a company asset and its quality is your responsibility.
• Government criteria characterization and documentation. Detect, track, and identify performance measured against published counter-small-UAS characterization criteria, documented cleanly enough to submit in a federal proposal without rewriting.
• Radome and enclosure effects and computer vision integration. Detuning, loss, and pattern distortion from the housing. You work with mechanical engineering so the antenna that passed on the bench still passes inside the box, outdoors, in Caribbean heat and humidity.

The number you produce is the number that goes into a product and into thd test report. Nobody downstream re-derives it. That is the weight of the seat, and it is why we will hand it to someone early in their career who has clearly earned it.

B.S. in Electrical Engineering or Physics. Recent graduates through roughly 5 years of experience. Hands-on work counts wherever you did it: coursework, senior design, student competition, amateur radio, or a bench in your apartment. We care that you have done it, not who paid you to.

• You have built something that radiates. An antenna you fabricated, tuned, and measured. Tell us what it was, how you built it, and how you knew it worked.
• RF fundamentals, applied. dB math, link budgets, free space path loss, multipath and fading, noise figure and sensitivity, receiver dynamic range, filters, LNAs, mixers, amplifiers, transmission line and connector loss. You reason in RF, you do not look it up mid-conversation.
• Antennas, hands-on. Antenna types and when to use each: dipole, monopole, patch and microstrip, Yagi, log-periodic, spiral, and arrays. Impedance matching and matching networks. Return loss, and bandwidth. Gain and pattern measurement, in a chamber or by open-field comparison. You have built, tuned, or characterized a working antenna and you can explain how you knew it worked.
• SDR modulation and demodulation. Digital modulation and how it looks in IQ: FSK and GFSK, BPSK, QPSK, QAM, OFDM, DSSS, and frequency-hopping spread spectrum. Baseband sampling, decimation and filtering, symbol timing and carrier recovery, constellation and spectrogram interpretation. You can look at raw IQ and say what the signal is doing.
• SDR platforms, hands-on. GNU Radio, UHD or SoapySDR, and real SDR hardware, including low-cost receivers. Python for collection, processing, and plotting. Linux comfort.
• Lab instrumentation. Spectrum analyzer, VNA, signal generator, oscilloscope, power meter. You know what a calibration is for and why it expires.
• Method over conclusions. If the measurement says the product underperforms, we need to hear it from you first, and we will act on it, not argue with it.
• Prototyping. Comfortable at a bench with a soldering iron. Any of: RF PCB layout, sheet metal, 3D printing, machining. You can get from a drawing to a physical part you can measure.
• U.S. person under ITAR.
• Onsite in San Juan, and in the field, outdoors, carrying gear.

Preferred: electromagnetic simulation, HFSS, CST, FEKO, openEMS, or NEC. RF PCB layout and 50-ohm design practice. Direction-finding array design. Circular polarization. UAS or drone hands-on time. Clearance eligibility. Spanish.

• Base salary within the posted range, set by demonstrated capability.
• Stock options in the Delaware parent, subject to board approval.
• Health, dental, flexible PTO.
• Direct mentorship from our CTO who shipped perception systems at consumer scale, and a founder who spent years on the receiving end of this threat.
• In your first year you will characterize a fielded defense system against a real government criteria set. Very few engineers get that in their first five.