A sensor system including an implantable sensor and an external transceiver. Aspects of the sensor system may provide improved implantation and antenna orientation of the implanted sensor. The sensor may include a sensor antenna, the transceiver may include a transceiver antenna. In some embodiments, the sensor antenna and/or transceiver antenna may include a first set of coils oriented in a first plane and a second set of coils oriented in a second plane that is different than the first plane. In some embodiments, the sensor may have a geometry that will prevent or reduce movement and/or rotation of the implanted sensor. For instance, in some embodiments, the sensor may be enclosed in silicon that contains antenna coils and/or include wings, a fluid filled sack, a swelling material, an expansion material, and/or arms.