ciency are shown in Figure 8. Over the GSM850/900 band shown in Figure 8(a), the antenna gain varied from about 0.7-1.6 dBi is seen, and the radiation efficiency is all larger than 55%. For the DCS/PCS band [see the results in Fig. 8(b)], the antenna gain is varied from about 2.0 -3.0 dBi, and the radiation efficiency is all larger than 70%.
CONCLUSIONA novel printed hybrid antenna consisting of a meandered loop antenna and a monopole slot antenna for GSM850/900/DCS/PCS operation in the mobile phone has been presented and successfully fabricated. The meandered loop antenna and the monopole slot antenna can be configured to occupy a compact volume at the top portion of the mobile phone and series-fed by a 50-⍀ microstrip feedline. With a small volume of 5.5 ϫ 6 ϫ 60 mm 3 only, which is Ͻ2 cm 3 , the hybrid antenna can generate two wide operating bands at about 900 and 1900 MHz to cover GSM850/900/DCS/ PCS quad-band operation. Good radiation characteristics of the hybrid antenna have also been observed. Moreover, with the incorporation of the meandered loop antenna and the monopole slot antenna, the proposed hybrid antenna are generally not sensitive to the groundplane length variations in the mobile phone, which is attractive for practical mobile phone applications.