In general, the disclosure is directed to a patient programmer for an implantable medical device. The patient programmer may include one or more of a variety of features that may enhance performance, support mobility and compactness, or promote patient convenience. The patient programmer includes an internal antenna mounted on a first circuit board and a display mounted on a second circuit board. The first circuit board includes a substantially contiguous ground plane layer that is interrupted by two or more gaps. The patient programmer may also include one or more of a variety of features that may enhance performance, support mobility and compactness, or promote patient convenience.