FIG. 1: (Color online) Top: A cross sectional view of a conventional CPW transmission line and the microstrip transmission lines used in this paper. Bottom: An optical microscope image of the a portion of the tested device. The inset on the lower left shows a SEM image of the cross section of a device that has been cleaved. The inset SEM image was used to determine the dielectric thickness d = 200 nm, the top aluminum wiring layer thickness of t$_{1}$ = 154 nm, and the bottom aluminum wiring layer thickness of t$_{2}$ = 93 nm. of reaching base temperatures below 100 mK. A coaxial feedline drives the device through a 30 dB attenuator at 4 Kelvin, and a high electron mobility (HEMT) amplifier with a noise temperature T$_{n}$ ≈ 5 . 5 K is used to boost the output signal. A cryoperm magnetic shield is used to shield the device, and a Helmholtz Coil internal to the magnetic shield is used to apply a magnetic field normal to the surface of the chip. Microstrip resonators, like larger CPW resonators[18], appear to be quite sensitive to the magnetic field normal to the metal surface during cooling through the superconducting transition temperature T$_{c}$ . Figure 2 shows the applied magnetic field during cooling and the resulting quality factors of the lowest Q$_{m}$ resonator on the device. Despite the magnetic shield the best quality factor is achieved with an applied magnetic field of around 30 mG. 5