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Wen-Tung Hsu,1 Deng-Ho Yang,1– 4 Chun-Cheng Liao,3,5 Jia -Wen Chen,6 Wen-Hsiu Hsu,3,7 Chia-Wen Kuo,3,8 Hung-Chang Hsu,9 Sheng-Huang Chang,10 Li-Mien Chen2,3 1Division of Laboratory, Taichung Armed Force General Hospital, Taichung, Taiwan, Republic of China; 2Department of Internal Medicine, Taichung Armed Force General Hospital, Taichung, Taiwan, Republic of China; 3School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China; 4Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan, Republic of China; 5Department of Family Medicine, Taichung Armed Force General Hospital, Taichung, Taiwan, Republic of China; 6Medicine Laboratory, Ministry of Health and Welfare Feng Yuan Hospital, Taichung, Taiwan, Republic of China; 7Division of Gastroenterology, Taichung Armed Force General Hospital, Taichung, Taiwan, Republic of China; 8Division of Nephrology, Taichung Armed Force General Hospital, Taichung, Taiwan, Republic of China; 9Division of Laboratory, Ching Chyuan Hospital, Taichung, Taiwan, Republic of China; 10Tsaotun Psychiatric Center, Ministry of Health and Welfare, Nantou, Taiwan, Republic of ChinaCorrespondence: Li-Mien ChenDepartment of Internal Medicine, Taichung Armed Force General Hospital, No. 348, Sec. 2, Chung-Shan Road, Taiping, Taichung, Taiwan, Republic of ChinaEmail c332860@ms65.hinet.netPurpose: To evaluate the blood glucose and renal function, determine the prevalence of hyperglycemia/diabetes mellitus (DM) and renal disease (nephropathy), and investigate the association between hyperglycemia/DM and renal disease in patients with viral hepatitis (VH).Patients and Methods: A total of 491 subjects were included in the study. Patients with VH were further divided into the hepatitis B virus (HBV) infection, hepatitis C virus (HCV) infection, and HBV-HCV co-infection subgroups. Fasting blood glucose, glycated hemoglobin (HbA1c), glycated albumin (GA), glutamic oxaloacetic transaminase (GOT), creatinine (Cr), and cystatin C (Cys C) levels were measured. Urine microalbumin levels were also assessed. Formulas for estimated average glucose calculated using glycated albumin(eAG(GA)), estimated average glucose calculated using HbA1c (eAG(HbA1c)), and estimated glomerular filtration rate calculated using cystatin C (eGFRcys) were used to evaluate the average glucose and renal function.Results: The prevalence of hyperglycemia/DM and renal disease was significantly higher in the VH group, especially in the HCV subgroup. The prevalence of renal disease was significantly higher in patients with VH with eAG(GA) ≥ 200 mg/dL.Conclusion: Our study used multiple parameters to evaluate blood glucose and renal function in patients with VH and found that hyperglycemia/DM and renal disease are closely associated with VH, especially in subjects with HCV infection. Patients with VH, especially those with HCV infection and hyperglycemia/DM, were particularly vulnerable to renal disease.Keywords: viral hepatitis, hyperglycemia, diabetes mellitus, renal disease, nephropathy

A dual feed vertical polarization circular array antenna for WLAN and 5G (sub-6 GHz) small-cell base station applications have been presented. The proposed antenna is a 2×2 array antenna that formed by 4 circular patch elements, two antenna ports, two feeding network circuits and a PCB with ground plane. This antenna design provides a wide frequency operating band Covering the WLAN and 5G (sub-6 GHz) smallcell base station band. The antenna is designed for 1/2 wavelength characteristics. The dielectric material of the antenna is an FR4 board with a ground plane size of 127 x 127 x 2.8 mm3. The feed port uses a matching network to convert 50 ohms and uses 50 ohm SMA connectors on each of the two feed ports. Finally, the circular patch size is modified to achieve the desired operating band.

This paper proposed a design to improve the high isolation of the MIMO slot antenna, which can be applied to WLAN 2.4 (2.4 - 2.48 GHz), WLAN 5.2 / 5.8 (5.15 - 5.85 GHz). The antenna design will be fed into the microstrip line design in the rectangular diagonal part of the excavation of a corner edge, the antenna placed in a mirror way, by adjusting the length of the slot and feeding microstrip line position to control the high and low frequency, And then effectively stimulate the WLAN required operating frequency band, and can effectively reduce the current coupling overflow to the other end of the slot, the low frequency band has a good isolation, from -4.5 dB to -24.5 dB, while the high frequency band is higher than -15 dB.

The paper presents an antenna design of smart watch with WLAN MIMO antennas and a GPS antenna. The overall dimensions size of the design is 40 mm × 40 mm × 5.4 mm. There are four WLAN antennas and a GPS antenna in the design. The size of ground plane is 40 mm × 40 mm. The antennas are fed by 50-ohm mini coaxial cable line. The PIFA type is adapted to design the antennas of GPS (1.575 GHz) and WLAN (2.4 – 2.484 GHz) band. The four WLAN antennas are placed on proximity of the four corners of four border of the smart watch; the GPS antenna is placed the part of the ring of the smart watch. The simulated and measured S ii (I = 1 to 5) results are below of −6dB and isolation between these antennas are also larger than 10dB.

Appendicitis is the most common abdominal disease that requires surgery in the emergency ward. It usually presents as right lower quadrant pain, but may rarely present as left upper quadrant (LUQ) pain due to congenital anatomical abnormalities of the intestine. We report a patient who complained of persistent LUQ abdominal pain and was finally diagnosed by computed tomography (CT) as congenital intestinal malrotation complicated with acute appendicitis. It is important to include acute appendicitis in the differential diagnosis of patients who complain of LUQ abdominal pain. Abdominal CT can provide significant information that is useful in preoperative diagnosis and determination of proper treatment.

This paper proposed an open slot handsets antenna with a capacitor and shorting feed, it can be applied to LTE700 (698–787MHz), LTE2300 (2300–2400MHz), LTE2500 (2500–2690MHz), GPS (1575MHz). This antenna is designed by a quarter-wavelength resonant mode, and fabricated on a FR4 substrate. In the top portion of the ground plane there is an open slot structure fed by a 50-Ω microstrip line, its endpoint with a capacitor load for impedance matching, across the slot. By adjusting the length of the slot, ground path, position of microstrip line and embedding a capacitor, the antenna can be controlled its high-band, middle-band and low-band modes; thus an effective coverage of the LTE/GPS operation frequency band can be achieved.

A coupled-fed monopole antenna with a multi-arm structure for GSM900/GSM1800 / DCS / PCS / UMTS / LTE2300 for USB dongle is presented. The monopole is fed by 50-ohm mini coaxial cable line. The two arms are on the front side and a meandered arm extended from the front side by via is on the back side. The multi-arms are coupled by an inverted L strip connected to feed point. The arms resonance of the bands, including: GSM900 (0.89–0.96 GHz), GSM1800 (1.71–1.99 GHz), DCS (1.71–1.88 GHz), PCS (1.85–1.99 GHz), UMTS (1.92–2.17 GHz), LTE2300. The simulated and measured results are proposed and discussed in the paper.

A monopole slot antenna with compact size designed at WLAN band (2.4–2.484 GHz) is proposed for multiple-input multiple-output application. By the concept of electromagnetic shield, the antenna module is formed by an open-ended monopole slot surrounded by another open-ended monopole slot on the ground plane. The two identical folded antenna modules located on the both side of the ground plane are separated by an isolated element for increasing isolation more than 17.8 dB within the operating band. To increase antenna's bandwidth, the two open-ended monopole slot antennas with different lengths are printed to obtain two resonant modes, which are close at around 2.4 GHz. In addition, the proposed antenna occupies a small area of 10.5 × 20 mm2 and can be easily fabricated on an FR4 substrate that is a commonly used circuit board. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1103–1107, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26740

Tournefortia sarmentosa Lam. (Boraginaceae), a Chinese herbal medicine, is commonly used as a detoxicant or anti-inflammatory agent.As acetaminophen (APAP) is a well-known hepatotoxin, we investigated the effect of the aqueous extract of the T. sarmentosa on APAP-induced hepatotoxicity in vivo and in vitro.Levels of liver function markers serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), and alkaline phosphatase (ALP), inflammatory markers tumor necrosis factor (TNF)-α, interleukin (IL)-1b, and IL-6 in serum, and antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), as well as lipid peroxidation were determined.T. sarmentosa significantly reduced the elevated liver function (SGOT, SGPT, and ALP, p 0.01) and inflammatory markers (TNF-α, IL-1β, and IL-6, p 0.01) in serum of APAP-intoxicated rats. Malondialdehyde level (p 0.05) and antioxidant enzyme levels (CAT, SOD, and GPx, p 0.05) were also reduced in APAP-intoxicated rats treated with T. sarmentosa. Incubation of rat hepatocyte cell line clone-9 cells with APAP reduced cell viability and increased the extent of lipid peroxidation. APAP stimulation also reduced the level of glutathione (GSH) and caused reduction in the activities of the antioxidant enzymes, CAT, SOD, and GPx. Pretreatment of hepatocytes with T. sarmentosa aqueous extract before and during APAP stimulation attenuated the extent of lipid peroxidation, increased cell viability and GSH level, and enhanced the activities of antioxidant enzymes.These data suggest that the aqueous extract of T. sarmentosa can prevent APAP-induced hepatotoxicity.

Adiponectin is considered a modulator of glucose metabolism. Hypoadiponectinemia was reported to be associated with glucose metabolism and metabolic syndrome, and had been found in patients with hepatitis B virus (HBV) and hepatitis C virus infections. However, little is known about the role of adiponectin in patients with HBV infection. Fifty-five patients with HBV infection and 52 healthy individuals were included in this study. We found that serum adiponectin was significantly lower in patients with HBV infection. We also found that HBV-infected patients with hemoglobin A1C ≥6.5% had a lower adiponectin level than those with hemoglobin A1C

Berberine is the major constituent of Coptidis Rhizoma with multiple pharmacological activities, including anti-inflammation, promotion of apoptosis and anticancer potential effect. Mitogen-activated protein kinase (MAPK) and reactive oxygen species (ROS) may contribute to the causal relationship between tumorigenesis and pro-apoptotic function. Berberine is studied for the mechanism of its action in apoptotic pathway in human colonic carcinoma cell. Treatment of SW620 cells with 50 microM berberine resulted in activation of the caspase 3 and caspase 8, cleavage of poly ADP-ribose polymerase (PARP) and the release of cytochrome c; whereas, the expression of BID and anti-apoptosis factor c-IAP1, Bcl-2, and Bcl-(XL) were decreased markedly. Berberine-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of JNK and p38 MAPK, as well as generation of the ROS. Furthermore, the induction of apoptosis was alleviated by inhibitors specific for JNK and p38. In addition, there was an increase in the cellular levels of phospho-c-Jun, FasL and t-BID in the berberine-induced apoptosis via the activation of JNK and p38 signaling modules. NAC administration, a scavenger of ROS, reversed berberine-induced apoptosis effects via inhibition of JNK, p38 and c-jun activation, and FasL and t-BID expression. These results leads us to speculate that berberine may play an apoptotic cascade in SW620 cells by activation of the JNK/p38 pathway and induction of ROS production, providing a new mechanism for berberine-induced cell death in human colon cancer cells.

This study proposed a high gain dipole antenna system with reflective metal sheet. The structure of this system was simple. An antenna unit was composed of a symmetric trapezoid-shaped dipole antenna, and an antenna system was constructed by placing metal reflective metal sheet, which were formed on single-sided base plate (FR4), of the same structure with a certain spacing. The area of the antenna system was 43 × 10 mm2. A 50 Ω copper coaxial cable was connected to the center of the antenna unit as the antenna feed. This system was designed specifically for WLAN applications. Having a frequency band of 2.4–2.485 GHz, the proposed antenna system had good directivity, and the gain was approximately 6.0–6.2 dBi.

Acute porphyrias are rare diseases with varying incidences worldwide. These diseases are disorders of heme biosynthesis characterized by acute attacks of neurological symptoms. Acute porphyria should be considered in patients with unexplained abdominal pain or neurological damage. Clinical manifestations of acute porphyria are nonspecific and are associated with multiple organ systems. This report examines a rare case of an uncommon type of acute porphyria in a patient with an initial presentation of abdominal pain and progressive polyneuropathy.

A broadband probe-fed patch antenna with a novel three-dimensional (3D) U-shaped ground plane is proposed and experimentally studied. The proposed antenna has a thick air substrate, and by placing the two flanges of the U-shaped ground plane in parallel to and at a suitable distance from the radiating edges of the antenna's radiating patch, a wide impedance bandwidth (>25%) with much reduced cross-polarization radiation can be obtained, compared to the case with a conventional planar ground plane. In addition, enhanced antenna gain for the proposed antenna is also observed. Details of the proposed antenna and experimental results are presented and discussed.

This paper presents an omnidirectional high-gain dual-mode dipole antenna design with simple architecture. The proposed antenna system was composed of a rectangular antenna main body and a reflective ground plane. The antennas was "H" shaped and fabricated on a single-sided FR4 substrate. The area of the antenna system was 53 × 31 mm2, and a 50Ω micro-strip was used as a feeding pin at the center of the rectangular antenna main body. This antenna design included two frequency band ranges. For the Global Positioning System (GPS), the 1.57542 GHz frequency band was used. For WLAN, the 2.4–2.485 GHz frequency band was used. In the GPS frequency band the proposed antenna exhibited good omnidirectional properties and gain of 1.6–1.7 dBi. In the WLAN frequency band the proposed antenna exhibited good directional properties and gain of 6.2–6.3 dBi. This antenna design showed excellent performance when used for GPS and WLAN.

Background Resistin, adipocyte-secreting adipokine, may play critical role in modulating cancer pathogenesis. The aim of this study was to investigate the effects of resistin on HCC adhesion to the endothelium, and the mechanism underlying these resistin effects. Methods Human SK-Hep1 cells were used to study the effect of resistin on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expressions as well as NF-κB activation, and hence cell adhesion to human umbilical vein endothelial cells (HUVECs). 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR), an AMP-activated protein kinase (AMPK) activator, was used to determine the regulatory role of AMPK on HCC adhesion to the endothelium in regard to the resistin effects. Results Treatment with resistin increased the adhesion of SK-Hep1 cells to HUVECs and concomitantly induced NF-κB activation, as well as ICAM-1 and VCAM-1 expressions in SK-Hep1 cells. Using specific blocking antibodies and siRNAs, we found that resistin-induced SK-Hep1 cell adhesion to HUVECs was through NF-κB-regulated ICAM-1 and VCAM-1 expressions. Moreover, treatment with AICAR demonstrated that AMPK activation in SK-Hep1 cells significantly attenuates the resistin effect on SK-Hep1 cell adhesion to HUVECs. Conclusions These results clarify the role of resistin in inducing HCC adhesion to the endothelium and demonstrate the inhibitory effect of AMPK activation under the resistin stimulation. Our findings provide a notion that resistin play an important role to promote HCC metastasis and implicate AMPK may be a therapeutic target to against HCC metastasis.

Internal hernia is an unusual cause of intestinal obstruction, and the through sites of hernias may include the paraduodenum, transmesenteric region, foramen of Winslow, paracecum, the broad ligament of the uterus, and the transomental region. Transomental hernia is the rarest type of internal hernia and accounts for fewer than 1% of internal hernias. Transmesenteric and transomental hernias are different from the other types of internal hernia, and usually present acute intestinal obstruction with strangulation of the small bowel. We report a 74-year-old male with initial manifestation of peritonitis. Internal hernia-induced intestinal obstruction with strangulation was highly suspected from the image study. After an urgent exploratory laparotomy, transomental hernia was diagnosed.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder with involvement of multiple organs. Various forms of serositis, including pleural effusion, pericardial effusion, and ascites, may be found during the course of SLE. Peritoneal involvement by ascites is common in the initial presentation of SLE. However, chylous ascites is uncommon in SLE patients. Here, we describe a 93-year-old female with initial presentation of chylous ascites during SLE flares. Marked distention and an ovoid shape of the abdomen were observed. Shifting dullness and central tympanic sounds were found on percussion. Rales were heard in bilateral breathing sounds, multiple oral ulcers appeared in the oral cavity, and chest images showed bilateral pleural effusion. Abdominal sonography revealed moderate ascites and pleural effusion. Neither organisms nor malignant cells were revealed in the culture or cytology of ascites and pleural effusion. The diagnosis of SLE was arrived at by positive antinuclear antibody (ANA), discoid rash, oral ulcers, serositis (pleural effusion and ascites), and proteinuria. The patient received intravenous methylprednisolone 250 mg/day for three days. The pleural effusion resolved dramatically after steroid therapy and abdominal distention related to ascites formation subsided obviously.

The printed loop antenna for multi-frequency operation in the mobile phone application is proposed. The loop antenna consists of an inverted-L shaped strip and a rectangular patch on the front side, while the back side consists of a meander loop antenna and a 100×60 mm2 ground plane. The inverted-L shaped strip and the rectangular patch are connected with a 50 Ω microstrip line. The feeding mechanism is coupled-fed method, which excites the loop antenna through the inverted-L strip and the rectangular patch. The loop antenna provides two wide operating bands centered at about 810 and 2175 MHz for LTE700/GSM850/GSM900/DCS/PCS/UMTS/LTE2300/WLAN/LTE2500 bands operation. The proposed antenna also has the advantages of low profile, low cost, ease fabrication, and less affected by changing ground plane size.

Both the urokinase-type plasminogen activator (uPA) and the uPA receptor (uPAR) play important roles with regard to hepatocellular carcinoma (HCC) progression and metastasis. Notably, the stromal cell-derived factor-1 (SDF-1) is an important chemokine involved in HCC pathology. However, the influence of uPA on SDF-1 expression in human HCC cells remains unknown. We investigated the mechanisms underlying the modulation of SDF-1 expression through uPA stimulation in human HCC SK-Hep-1 cells. SK-Hep-1 cells stimulation with uPA induced increases in the expression and secretion of SDF-1. By using specific inhibitors and small interfering RNA, we have demonstrated that the activation of extracellular signal-related kinase (ERK) and c-Jun-NH2-terminal kinase (JNK) pathways are critical for uPA-induced SDF-1 expression. Transcription factor ELISA and chromatin immunoprecipitation assays suggest that uPA increase Sp1- and AP-1-DNA-binding activities in SK-Hep-1 cells. Inhibition of Sp1 and AP-1 activations by specific siRNAs blocked the uPA-induced SDF-1 promoter activity and expression. The effect of uPA on SK-Hep-1 signaling and SDF-1 expression is mediated by uPAR. In summary, our findings serve to elucidate the uPA/uPAR downstream signaling, providing new insight into the function of uPA in HCC cells. J. Cell. Physiol. 227: 697–704, 2012. © 2011 Wiley Periodicals, Inc.

This paper designs a monopole antenna on a commonly used FR4 substrate with width of 0.8 mm. The overall dimensions of the proposed antenna are 45×94.5 mm2, which can be easily applied in today's mobile devices. With small size of radiation element (45×12 mm2), the proposed antenna consists of three resonant paths that operate three resonant bands. By carefully adjusting the length of antenna paths and gap between antenna paths, the 6-dB operation bands (824–1000 MHz and 1710–2182 MHz) can be applied in GSM850, GSM900, PCS, DCS, and UMTS application bands. Both simulated and measured results are presented and discussed.

A well placement design to improve GSM/DCS and GPS antenna isolation is proposed. The GSM/DCS antenna comprises two branches that the longer one is for GSM900 and the shorter one is for DCS1800. The proposed main antenna has an impedance bandwidth of 104 MHz and 187 MHz respectively in GSM900 and DCS1800 bands, with VSWR of 3∶1. The GPS subsidiary antenna works in L1 band (1575.5 MHz). The isolation between GSM900/DCS1800 and GPS antennas is over 21.3 dB. The more experimental results and analysis will be presented.

This paper presents a design using dual capacitive feeds to excite a patch antenna with a thick air substrate to achieve a wide operating bandwidth with reduced cross-polarization radiation. The dual capacitive feeds are fed by equal input powers, but with a 180° phase shift, and have a narrow conducting strip placed below the radiating patch, supported by a conducting post, which is then connected, through via holes in the ground plane, to the microstrip feed network. Experimental results show that the proposed antenna can have greatly reduced cross-polarization radiation across the entire operating bandwidth, compared to the case with a single capacitive feed. Details of the proposed antenna and experimental results are presented. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 26: 169–171, 2000.

A new approach in designing a multiband monopole antenna is illustrated. The planar monopole antenna area has the size of 14mm in height and 30mm in width. With inserting a sinuous route in the outside sub-patch, which lower the lower band frequency and enhance the height band frequency bandwidth. The proposed antenna was fabricated and tested. The results showed a good agreement with the simulated ones. Due to the reduced size and capable of multiple operating bands, this type of antenna can be used in multiband mobile phone for GSM900/DCS/PCS/UMTS and GPS applications. Details of the proposed antenna design are described in this paper, and experimental results of the constructed prototype are presented.

The planar monopole antenna with a parasitic shorting stub is printed on the double-side FR4 substrate, with thickness 0.4 mm and relative permittivity 4.4, and fed by a 50 Ω microstrip line. The antenna patch has the size of 23 × 10.2 mm2 and consists of two resonant elements, a T-like monopole and a parasitic shorting stub. Due to the reduced size and capable of multiple operating bands, including 1.8, 1.9, 2.0, 5.2 and 5.8 GHz, it can be used in multi-band mobile phone for DCS (Digital Communication System), PCS (Personal Communication System), UMTS (Universal Mobile Telecommunications System) and UNII (Unlicensed National Information Infrastructure) 5-GHz radio band applications. Details of the proposed antenna design are described in the follow, and experimental results of the constructed prototype are presented.

A new and simple technique for obtaining circular polarization (CP) radiation of a single-feed microstrip antenna is demonstrated. This CP design is achieved by insetting a single slit to the boundary of the microstrip patch, and placing a single feed along an axis 45° to the one containing the slit. Applications of this CP design method to square and circular microstrip antennas have been implemented. Typical experimental results are presented and discussed. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 18: 306–308, 1998.

A variety of dual-frequency microstrip antennas have been previously reported. However, it is noted that these dual-frequency designs usually support limited tunable frequency ratios for the two operating frequencies. To provide a very flexible frequency ratio for a single-feed dual-frequency microstrip antenna, the design with two circular patches has also been shown. Such a design, however, uses a relatively complicated matching network between the two patches. We present a new structure of using an inset-microstrip line to simplify the matching network, which makes the present proposed design simpler and easier to be constructed. The proposed design method applied to two rectangular patches has been successfully implemented. The obtained frequency ratio of the two operating frequencies can be flexible, and good dual-frequency performances are also observed. Details of the antenna design and experimental results are presented and discussed.

Broadband patch antennas with a thick air or foam substrate have been of considerable interest owing to their simple structure, easy fabrication, and good radiation characteristics over a wide operating bandwidth. However, when such broadband patch antennas are to be excited using a probe feed, achievable bandwidth is usually limited to be less than 10%, due to the large inductance associated with the longer probe in the thick substrate layer. To overcome this problem, there are usually some compensations or modifications to be introduced in the feed arrangement or some slot loadings to be added to the radiating patch. In this article we demonstrate a new and simple broadband design of a patch antenna with a pair of wide slits. The wide slits are inserted at the boundary of a circular patch or at one of the radiating edges of a rectangular patch. The proposed broadband patch antenna can have similar wide impedance bandwidth and good radiation characteristics as those reported for a U-slotted patch antenna. Details of the antenna design and experimental results are presented and discussed.

A broadband shorted-patch antenna fed by an aperture-coupled feed with an H-shaped coupling slot is proposed and experimentally studied. By using an air substrate with a thickness of about 0.07 of the free-space wavelength of the center operating frequency, the proposed antenna can have an impedance bandwidth of about 26.2%, which is comparable to the conventional broadband probe-fed patch antenna with a U-slotted or E-shaped patch. Good broadside radiation patterns for the proposed antenna are also observed. Details of the proposed antenna and experimental results are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 306–307, 2001.

A new design of a circular patch antenna with an impedance bandwidth greater than 25% and a peak antenna gain about 8.3 dBi is presented. The circular patch antenna has a thick air substrate, and a pair of wide slits are cut in the circular patch to facilitate the antenna's impedance matching. The circular patch is supported by a conducting post, which is also connected to a 50 Ω microstrip feed line. The ground plane of the microstrip line also serves as the ground plane of the circular patch antenna, and the substrate of the microstrip feed line and the circular patch are on the same side of the ground plane. Details of the antenna design and experimental results are described. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 25: 327–328, 2000.

A wideband circular-E patch antenna with an air substrate and a capacitive feed is proposed. The circular-E patch is formed by inserting a pair of wide slits at the boundary of a circular patch, and the capacitive feed has a small metallic disk placed below the circular-E patch, supported by a conducting post, which is then connected to a 50 Ω SMA connector through a via hole in the ground plane of the patch antenna. A prototype of the proposed antenna is constructed, and experimental results reveal that a group of three adjacent resonant modes can be excited, which results in a wide 10 dB return-loss impedance bandwidth of about 35%. Acceptable radiation characteristics for operating frequencies across the obtained wide impedance bandwidth are also observed, and the gain variation within the bandwidth is seen to be less than 1.4 dBi, with a peak antenna gain of about 7.9 dBi. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 134–135, 2000.

Novel design of a dual-frequency triangular microstrip antenna with a V-shaped slot is proposed and experimentally studied. By selecting suitable dimensions of the V-shaped slot, dual-frequency operation with the frequency ratio ranging from 1.488 to 1.834 has been obtained using a single probe feed, and the two operating frequencies are of parallel polarization planes. Typical experimental results of the proposed design are presented and discussed. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 20: 133–134, 1999.

A novel disk-sector microstrip antenna with specific flare angles for circular polarisation (CP) operation is proposed and experimentally studied. Results show that by selecting the flare angle of the disk-sector microstrip patch to be 65 or 70/spl deg/, right hand or left-hand CP radiation can easily be obtained using a single probe feed. Details of the design considerations are described, and measured CP characteristics are presented.

The broadband design of a triangular microstrip antenna with a U-shaped slot is demonstrated. With a foam substrate of thickness /spl sim/0.08 /spl lambda//sub 0/, a slotted triangular microstrip antenna with an operating bandwidth of /spl sim/18% is obtained, which is /spl sim/1.8 times that of a corresponding simple triangular patch antenna. Details of the antenna design and experimental results are presented.