Abstract-This paper introduces a mobile switchable antenna for long term evolution (LTE) of the 4th generation (4G), applicable to all mobile service bands. The validity of this antenna is assessed by design, realization, and measurement. A new frequency-selecting method is used in the proposed antenna, based on capacitance switching among four states. Due to the limited antenna space in existing terminals, it is quite difficult to cover the entire low band with a single antenna. To overcome this difficulty, three singlepole double-throw (SPDT) switches, one 74HC04, and four capacitors are used. The resulting antenna covers the LTE (698-798 MHz) and GSM (824-960 MHz) bands in the low-band characteristic by realizing four capacitance states and at the same time covers the DCS (1710-1880 MHz)/PCS (1850-1990 MHz)/WCDMA (1920( -2170 bands in the high-band characteristic. The antenna provides a gain of −1.04-6.00 dBi, a radiation efficiency of 32.73-74.99%, and omnidirectional characteristics in the H-plane. Because of this outstanding performance, it is expected that the new frequencyselecting technique will be applied in 4G mobile communication terminals.
, excluding those who visited for ambulatory treatment of systemic diseases. For the 90 subjects, we performed oral examination, measured Simplified Oral Hygiene Index (S-OHI), Modified Patient Hygiene Performance (PHP-M), and O ,Leary Index, and applied comprehensive dental hygiene control. First, as to the change of OHI according to age, the index in the 1st measurement was 3.43 in those under 35 and 3.17 in those aged 35 or older, so it was higher in the younger group, but in the 2nd measurement it was 1.89 in those under 35 and 2.14 in those aged 35 or older, and in the 3rd measurement it was 1.22 in those aged 35 or older, so it was higher in the older group. Second, as to the change of PHP-M according to age, the index in the 1st measurement was 50.35 in those under 35 and 43.16 in those aged 35 or older, soit was higher in the younger group, but in the 2nd measurement it was 31.97 in those under 35 and 28.88 in those aged 35 or older, and in the 3rd measurement it was 21.31 in those aged 35 or older, so it was higher in the older group.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.