We have designed and experimentally studied several systems of standard coaxial cables with different impedances which mimic the operation of so-called photonic structures like coupled photonic crystal microcavities. Using elementary cells of half-meter long coaxial cables, we got resonances around 100 MHz, a range of frequencies that can be easily studied with standard teaching laboratory apparatus. Resonant mode frequency splitting has been obtained in the case of double and triple coupled cavities. Good agreement between experimental results and the transfer matrix model has been observed. The aim here is to demonstrate that a standard coaxial cable system is a very cheap and easy to implement structure to explain to undergraduate students complex phenomena that usually occur in the optical domain. © 2021 Author(s).