Body Centric Wireless Networks (BCWN) communication systems are attracting the attention of many researchers, due to their importance in many aspects. It covers an extensive range of applications that are associated with many services. The fast development in 5G, 6G, and the Internet of Things (IoT) make investment and research in this area valuable. BCWN covers a wide range of applications such as Bio-medical and health care, tracking, sports, security, entertainment, military, etc. Wearable devices are the most important part of the BCWN. They can be worn by humans and can communicate with other devices. It mostly consists of an antenna, batteries, and sensors. It can be in various shapes such as bands, watches, glasses, shoes, wearable medical sensors, helmets, etc. The main part of wearable devices is the antenna that is used to transmit and receive signals. BCWN includes different types of body-centric links. This MSc thesis will be focusing on off-body links where the antenna is integrated into a wearable device and used to transmit/receive signals to/from another antenna outside the human body. This thesis focuses more on the design and optimization of the wearable reconfigurable antenna. In this case, a single antenna can operate at multi-bands, polarizations, or both by using multiple switching devices that change the status of the antenna instead of using several antennas that make the system complex and large in size. The antenna used in this thesis is a rectangular patch antenna with cuts at the corners connected by PIN (Positive- Intrinsic-Negative) diodes. By turning the diodes ON and OFF, different statuses are achieved. In this design only, by changing the statuses of the PIN diodes, three different polarizations and four different bands of frequencies can be achieved. The first case is when all diodes are in OFF status, the resonating frequency is at 2.45 GHz, with a bandwidth of 250 MHz (10.2%), and a gain of 4.61 dBi. The second case is with all PIN diodes being ON states. The resonating frequency shifted to 2.2 GHz with a gain of 2.91 dBi. Both the above-mentioned cases have linear polarization. In Cases three and four, half of the PIN diodes are ON and half are OFF, which can achieve resonating frequencies at 2.38 GHz and 2.37 GHz, with a gain of 4.19 dBi and 4.15 dBi respectively. The matching bandwidth for both bands are 380 MHz (16.5%) and 390 MHz (17%) respectively. The antenna has linear polarization at the resonating frequencies of 2.38 GHz and 2.37 GHz, and circular polarization at frequencies of 2.16 GHz, and 2.15 GHz for case three (RHCP) and case four (LHCP) respectively. Another improvement has been achieved by introducing a slot to the first case when all PIN diodes are in OFF status. The antenna resonating frequency shifts to the Super High Frequency range (SHF), resonating at 3.48 GHz with a gain of 7.61 dBi. A third antenna design was proposed as well by introducing PIN diodes to the slot gaps, seven other cases were presented and analyzed.