## 4 Specific Examples and Applications of Wearable Antenna Designs  
A large number of wearable antennas have already been proposed for many different applications including miniaturized rigid and flexible textile antennas. Examples of rigid miniaturized antennas are outlined in the first half of this section. A shorted spiral-like patch antenna operating at 430 MHz suitable for military Radio Frequency (RF) Communications was presented in [21]. This antenna was etched on FR4. The use of an electromagnetic bandgap (EBG) structure makes this antenna suitable for wearable applications by reducing the power radiated towards the wearer. The overall size of this antenna is 11.4 cm \(\times\) 7.6 cm, which is small compared to the wavelength at the resonant frequency. In [20] a dipole and a spiral antenna for military wearable applications (100-500 MHz) were proposed. These antennas are unobtrusive and low profile. In [59] three antennas: (a) \(\lambda_{\textrm{g}}\)/4 antenna with ground shield; (b) a dipole V antenna and (c) a square dipole antenna were made out of copper with a glass--epoxy substrate (\(\varepsilon_{r}=\)_4.8_) and proposed for operation 868 MHz, for medical tele-monitoring applications. These antennas would be more suitable for a patient to wear if they were textile which will make them more flexible and comfortable. In [60] [PERSON] presented a dual band (900 MHz & 2.4 GHz) Planar Inverted F-Antenna (PIFA) antenna for wearable applications suitable for the Global System for Mobile Communications (GSM) and for short range Bluetooth bands. The antenna was designed as a PIFA so as to radiate away from the human body. A dual mode antenna for on/off-body communications (10 MHz/2.45 GHz) was proposed in [61]. This antenna consists of an L-shaped slit loaded for the 2.45 GHz band (off-body link) connected with an electrode which is mounted on the body and is suitable for the 10 MHz (on-body) link. In [62] a four arm spiral slot patch antenna for radio telemetry capsules was proposed for operation at 915 MHz. In terms of miniaturization a reduced ground plane shorted patch antenna for on-body communications at 2.45 GHz was proposed by [PERSON] _et al_. [63] with a miniaturized (-\(\lambda\)/5) ground plane. A monopole antenna mounted vertically on the body radiates the same way (parallel radiation towards body surface) as this shorted patch [63]. However, this shorted patch proved to be more suitable for the on-body link because it is compact. In [64] a miniaturized diversity antenna dedicated to wireless body area network was proposed. The antenna was printed on FR4. The combination of a PIFA and a top-loaded monopole  
Figure 9: Embroidery machine creating FSS structure. yielded distinct patterns. The strong isolation observed between the broadside and the end-fire radiation of the antenna is a significant feature which limits the correlation between the received signals. Other miniaturized wearable antenna designs are detailed in [65, 66, 67]. Smart clothes evolution will eventually result in the establishment of textile antennas in widespread use. This may mean that clothes and wearable textile antennas or electronics will be designed as one piece. Examples of wearable textile antennas are outlined in the second half of this section. A textile antenna suitable for fire fighters jackets was presented in [68]. The substrate shell of jacket is made of aramid fabric which is fireproof. In [69, 70] a flexible dual band PIFA was proposed for commercial smart clothing. An inexpensive textile patch antenna for off-body wireless sensor communications for monitoring patients at the 915 MHz Industrial, Scientific and Medical (ISM) radio band is presented in [71]. Zelt was used for the conducting parts and felt for the substrate of this antenna. The cost per square meter of Zelt and Felt is equal to $20 [71]. With 1 square meter of these two materials we can fabricate about 5-6 such antennas. A dual band E-shaped patch textile antenna made from felt and copper tape is presented by [PERSON] in [72].