Abstract-Miniature fluxgate sensors with symmetrical closed core elements on both sides of the planar coils were manufactured using standard microtechnology. The new sensors have shown substantial improvement over the standard single-sided microfluxgate sensors: for the same field range the sensor noise was reduced 10-times to 20 nT rms (20 mHz . . . 10 Hz) and the perming suppressed below 5 T, for field shocks of 6 mT. The maximum sensitivity for sinewave excitation was 32 V/ T for 1 MHz frequency and 200 mA -excitation current amplitude. Pulse shape of the excitation current allows use of high current peaks to suppress perming, while the rms value is low. Using a 20% duty factor squarewave excitation with 180 mA -amplitude, the sensitivity was twice that of the sinewave excitation, while the chip temperature dropped from 80 C to 40 C.
Abstract-Printed circuit board (PCB) integrated inductors have been adapted for operation as fluxgate sensors. A ring core is made from an electrodeposited permalloy thin film and is sandwiched between the layers of the PCB. The sensor excitation winding is also integrated into the PCB design. The pick-up coil is wound around the frame of the PCB core. Different types of current excitation waveforms with tuned and nontuned pick-up coils were used. The achieved sensitivities for 60 turns of tuned/nontuned pick-up coil, a sinusoidal waveform excitation current of Irms = 300 mA, and an excitation frequency of 150 kHz were 13100/1800 V/T. The achieved sensitivity for pulse excitation (Ipeak-peak = 900 mA, Irms = 184 mA, duty 20%) was 2100 V/T. Noise power density for pulse excitation was 1.2 nTrms Hz@1 Hz, noise rms value from 10 mHz to 10 Hz was 3.3 nT. A perming error of 1 T was measured for a wide range of excitation currents.Index Terms-Excitation, fluxgate sensor, printed circuit board (PCB), temperature stability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.