Browsing by Author "Jou, CF"

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2.4 and 5.2 GHz dual-band antenna fabricated on flexible parylene membrane
(2005-12-01)
Huang, CU
;
Chen, IY
;
Chen, HJH
;
Jou, CF
;
Huang, SRS
A 2.4 and 5.2 GHz dual-band monopole antenna fabricated on a flexible parylene membrane for Bluetooth and wireless local area network (WLAN) modules was designed and fabricated. The measured results show a good antenna performance and agree very well with the design simulations in both return loss and radiation characteristics. Parylene is a flexible polymer film; it can be deposited on various substrates and peeled off after completing device processes as stand-alone thin-and-flexible-substrate-containing devices. Owing to its excellent physical and chemical properties such as its low dielectric constant, light weight, low conductivity, and inertness to chemicals, parylene is also suitable for fabrication of many other RF devices.
A back-to-back dual-beam active microstrip leaky-wave antenna array with mode-switching capability
(2000-02-05)
Hu, CC
;
Jou, CF
;
Wu, JJ
;
Peng, ST
;
傳播研究所
An X-band two-element back-to-back coupled-oscillator-driven spatial power-combining microstrip leaky-wave antenna array is developed, which has a dual-beam radiation pattern and mode-switching capability. Two Gunn diode CPW oscillators are placed on the back side of the substrate, each driving two back-to-back microstrip leaky-wave antenna pairs in opposite directions for dual-beam operation. This active antenna array is able to produce sum and difference patterns between the in-phase and 180 degrees out-of-phase mode by controlling the bias voltages of the Gunn diodes. (C) 2000 John Wiley & Sons, Inc.
A beam-forming technique for leaky-wave antennas
(2001-01-20)
Chen, IY
;
Wang, CJ
;
Liu, SJ
;
Jou, CF
;
傳播研究所
A beam-forming technique for leaky-wave antennas (LWAs) which can switch electronically in three different radiation patterns is developed in this letter. A simple two-terminal feeding microstrip-line LWA works as a radiating element. By varying the phase of the two injection signals from 0 to 180 degrees, the emitting power from the LWA can produce three different radiation modes: the normal mode (one sharp beam), the difference mode (Delta), and the sum mode (Sigma). The antenna displays large-bandwidth characteristics, and can be useful near crossroads for collision avoidance or in the radio location of vehicles. (C) 2001 John Wiley & Sons, Inc.
A concurrent 0.18-mu m CMOS self-biased dual-band driver amplifier for IEEE 802.11 a/b/g
(2004)
Jou, CF
;
Cheng, KH
;
Chen, JL
;
傳播研究所
;
Institute of Communication Studies
A 2.4 GHz / 5.2 GHz self-biased dual band CMOS driver amplifier with a 9.8-dBm output power using TSMC 0.18-mu m IP6M standard CMOS process is described. The CMOS amplifier designed on Rogers R04003 printed-circuit-board (PCB) with a single input and a single output signal chain is simultaneously optimized for wireless local area network (WLAN) 2.4 GHz / 5.2 GHz applications. Simulation results show that the driver amplifier exhibits an Output power about 9.7-dBm in both 2.4 GHz and 5.2 GHz, output interception point (OIP3) of 24dBm with power added efficiency (PAE) = 27% and PAE =24% in 2.4GHz and 5.2 GHz, respectively. The die size is 0.85x0.7 mm(2).
A CPW-to-Slotline active gunn diode leaky wave antenna
(1998)
Lee, SH
;
Wu, JJ
;
Peng, ST
;
Hu, CC
;
Jou, CF
A X-band coplanar waveguide (CPW) to slotline couple feeding active microstrip leaky wave antenna using Gunn-diode oscillator as source is demonstrated. The method to excite the first higher order mode of the microstrip leaky wave antenna is to put the CPW-to-slotline transition underneath the middle of the microstrip line, and the oscillator circuit and radiating element are separated by a ground plane. The measured angle of the maximum beam direction of active antenna is at 72 degrees for the active Gunn oscillator frequency of 11.218 GHz; This prototype of active leaky wave antenna feeding by Gunn diode oscillator with CPW-to-slotline structure can be easily scaled up to millimeter wave frequency region.
A dual-beam asymmetrically scanning leaky-wave antenna by utilizing a HEMT resistive upconverter
(2001-12-01)
Wang, CJ
;
Sheu, YH
;
Jou, CF
;
電信工程研究所
;
Institute of Communications Engineering
A dual-beam asymmetrical scanning microstrip leaky-wave antenna (LWA) has been demonstrated in this paper. A HEMT resistive upconverter output is connected to one terminal of the LWA, and a local oscillator (LO) signal is connected to the other terminal. In this experiment, we set the LO frequency at 9.5 GHz so that the right beam is fixed at 48degrees. By changing the IF frequency from 0.7 GHz to 1.5 GHz, the module of the LWA can steer the left main beam of the far-field pattern from 136degrees to 158degrees (the total scanning angle of 22degrees). Comparisons between the measured and theoretical results indicate that the design can achieve the asymmetrically scanning capability and agree well over the tuning bandwidth of 0.8 GHz.
A low power, fast-switching frequency synthesizer of 5.2GHz WLANs
(2004)
Cheng, KH
;
Chen, CH
;
Jou, CF
;
電信工程研究所
;
Institute of Communications Engineering
A 1.5V supply, low power consumption and fast switching integer-N frequency synthesizer is presented. The synthesizer consists of LC-tank VCO with quadrature output, D-type flip-flop (DFF) prescalar, swallow-counter, phase-frequency detector, charge pump and 4(th) order loop filter. A noble design procedure for loop filter is also presented with the aid of MATLAB program. The phase noise of VCO is -106dBc/Hz @1MHz offset. Total power consumption of synthesizer is 20.5mW. Settling time is 40us. The synthesizer is fabricated by TSMC 0.25um CMOS technology, and is suitable for HiperLAN II and IEEE 802.11a lower side-band applications.
A new two-terminal feeding active leaky-wave antenna
(1998-11-01)
Wang, CJ
;
Jou, CF
;
Wu, JJ
;
電信工程研究所
;
Institute of Communications Engineering
A new two-terminal feeding active-integrated leaky-wave antenna design is demonstrated. The S-band microstrip two-terminal feeding leaky-wave antenna is integrated with an active high-electron mobility transistor (HEMT) oscillator to produce a two-beam radiation pattern, The antenna is fed asymmetriclly at both sides to excite the first higher order mode, This configuration, as compared to a single-terminal feeding leaky-wave antenna, has the advantage of the multidirection and the reduction of the reflected wave caused by the open end of the radiating element. Measured results show that the radiation directions of two beams are approximately at 34 degrees and 140 degrees, the effectively isotropic radiated power (EIRP) is close to 17.5 dBm, and the return Loss is almost less than -10 dB between 9 and 11.5 GHz.
A new two-terminal feeding active leaky-wave antenna
(1998-11-01)
Wang, CJ
;
Jou, CF
;
Wu, JJ
;
傳播研究所
;
Institute of Communication Studies
A new two-terminal feeding active-integrated leaky-wave antenna design is demonstrated. The S-band microstrip two-terminal feeding leaky-wave antenna is integrated with an active high-electron mobility transistor (HEMT) oscillator to produce a two-beam radiation pattern, The antenna is fed asymmetriclly at both sides to excite the first higher order mode, This configuration, as compared to a single-terminal feeding leaky-wave antenna, has the advantage of the multidirection and the reduction of the reflected wave caused by the open end of the radiating element. Measured results show that the radiation directions of two beams are approximately at 34 degrees and 140 degrees, the effectively isotropic radiated power (EIRP) is close to 17.5 dBm, and the return Loss is almost less than -10 dB between 9 and 11.5 GHz.
A novel method for short leaky-wave antennas to suppress the reflected wave
(2003-01-20)
Wang, CJ
;
Guan, HL
;
Jou, CF
;
傳播研究所
;
Institute of Communication Studies
A method to suppress the back lobe of a short leaky-wave antenna (LWA) by using an aperture-fed patch antenna on the backside is demonstrated in this paper. The aperture-fed patch antenna is connected to the open end of the LWA. This design offers another radiation path of the reflected wave and creates another radiation pattern on the back plane of the substrate. Experimental results show that the suppression of the reflected wave can be 10 dB at 10.0 GHz with an LWA length of 6 cm (2 wavelengths). Compared to the conventional design, this novel structure can radiate as efficiently as LWA at a length a wavelengths. The two radiation patterns on different planes have great potential in many applications and can provide more flexibility to traditional designs. (C) 2003 Wiley Periodicals, Inc.
A novel two-beam scanning active leaky-wave antenna
(1999-08-01)
Wang, CJ
;
Jou, CF
;
Wu, JJ
;
傳播研究所
;
Institute of Communication Studies
A novel two-beam scanning active leaky-wave antenna (LWA) has been developed, This LWA with a two-terminal feeding microstrip line structure is integrated with a varactor-tuned X-band high-electron mobility transistor (HEMT) voltage-controlled oscillator (VCO). The signal of the VCO is injected via a T-divider into the radiating element. To excite the first higher order mode, the designed antenna is fed asymmetrically at both ends of the microstrip line. Compared with single-terminal feeding leaky-wave antennas, this configuration offers the advantages of dual-direction and suppression of the reflected wave caused by the open end of the radiating element. The scanning angle is steered over a range of 24-46 degrees for the right beam and 128-150 degrees for the left beam. The Effective isotropic radiated power (EIRP) is calculated to be 17.5 and 16.67 dBm at 10.4 GHz, respectively. The measured return loss S-11 is less than -10 dB in the range of 9-11.5 GHz, The transmission coefficient S-21 indicates that the power radiates into the space.
A two-dimensional beam-scanning linear active leaky-wave antenna array
(1999-03-01)
Hu, CC
;
Jou, CF
;
Wu, JJ
;
傳播研究所
;
Institute of Communication Studies
This letter presents a new technique fur electronic two-dimensional beam scanning using a phase-shifterless linear active leaky-wave antenna array. The varactor-tuned voltage-controlled oscillators (VCO's) and coupling network are implemented in this array. The measured pattern of this 4 x 1 leaky-wave antenna array shows that the main beam can be continuously scanned from 68 degrees to 40 degrees in elevation as the frequency varied from 8.24 to 9.15 GHz. By tuning the free-running frequencies of the end elements, the main beam can be continuously scanned from -26 degrees to +10 degrees in azimuth, A maximum ERP of 667 mW is measured at 8.9 GHz for this active antenna array.
Active aperture-coupled leaky-wave antenna
(1998-11-12)
Kao, NA
;
Hu, CC
;
Wu, JJ
;
Jou, CF
;
傳播研究所
An active aperture-coupled leaky-wave antenna which is integrated with a varactor-tuned high electron mobility transistor voltage-controlled oscillator (HEMT VCO) is presented. To excite the first higher mode of the microstrip, the aperture-coupled structure is used and a sequence of covered wire is added at the centre of this antenna to suppress the dominant mode. The measured H-plane main beam can be continuously scanned 10 degrees as the HEMT VCO frequency is varied from 9.05 to 9.5GHz. This feeding structure is very suitable for active phase antenna array applications.
Active asymmetrically feeding dual-beam leaky-wave antenna
(1998)
Wang, CJ
;
Jou, CF
;
Wu, JJ
;
Peng, ST
;
傳播研究所
An active-integrated dual-beam scanning leaky-wave antenna design is developed in this paper. A varactor-tuned oscillator HEMT VCO, an active source, integrates with an X-band two-terminal asymmetrically feeding microstrip leaky-wave antenna on the same plane. This approach creates a dual-beam radiation pattern and has the advantages of multi-direction and no reflected wave caused by the open end of the radiating element, as compared to a traditionally single-terminal feeding leaky-wave antenna. Measured results on the experimental antenna show that the total scanning angle of two beams of this antenna configuration is approximately 44 degrees The maximum Effective Isotropic Radiated Power (EIRP) are. close to 17.5 dBm for the right beam and 16.67 dBm for the left beam at 10.4 GHz,and the power difference between the two beams is less than 1 dB.
Active dual-beam aperture-coupled leaky-wave antenna
(1999-11-11)
Wang, CJ
;
Kao, NA
;
Jou, CF
;
Wu, JJ
;
傳播研究所
An active aperture-coupled leaky-wave antenna (LWA) with excellent dual-beam scanning capability is presented. An X-band varactor-tuned HEMT VCO is integrated on the other plane through an aperture with the LWA. This antenna has the advantages of multi-functionability, interference shielding, and a scanning main beam. The measured main beam in the elevation plane can be continuously scanned for 20 degrees for each beam as the HEMT VCO frequency is varied from 8.97 to 9.5 GHz. An effective isotropic radiation power of 18.89 dBm for the right beam and 19.06 dBm for the left beam is achieved.
Active feedback microstrip leaky wave antenna-synthesiser design with suppressed back lobe radiation
(1999-04-01)
Shih, YC
;
Chen, SK
;
Hu, CC
;
Jou, CF
;
傳播研究所
The design of an active leaky-wave antenna which integrates the antenna with a feedback synthesiser is introduced. The measurement result shows that the antenna has very low back lobe radiation compared with that of traditional single-terminal feeding leaky-wave antennas. Single frequency measurement shows that the radiated power differmce between the main beam and back lobe is >15 dB at 8.2 GHz For the designed feedback synthesiser antenna, the measured radiated power difference between the main beam and back lobe is >15dB at 9.25 GHz, and the scanning angle is similar to 5 degrees as the synthesiser frequency sweeps from 9.25 to 9.37 GHz.
Active frequency-tune beam-scanning leaky-wave antenna arrays
(1998-02-01)
Wang, CJ
;
Wu, JJ
;
Jou, CF
;
電信工程研究所
;
Institute of Communications Engineering
X-band active beam-scanning leaky-wave antenna arrays, including 1 X 1, 1 X 2 and 1 X 4 prototypes, have been demonstrated. These antennas integrated one or several microstrip leaky-wave antenna elements with a single varactor-tuned HEMT VCO as an active source. Measured results on experimental antennas indicate that the beam scanning angle of the 1 X 1 antenna close to 40(0) can be achieved and the scanning range of 1 X 2 and 1 X 4 antenna arrays are both close to 32(0), Furthermore, reflected wave due to the open end of each leaky-wave antenna element has been suppressed by the symmetric configuration of this antenna array and the antenna efficiency increases. When comparing with the measured radiation pattern of the single element antenna, we found that the 1 X 2 and 1 X 4 antenna arrays can effectively suppress the reflected power by more than 5.5 dB and 10.5 dB, respectively, at 10.2GHz. The power gain are more than 2 dB and 3.16 dB higher than the single element antenna with a measured EIRP of 18.67 dBm.
Active frequency-tune beam-scanning leaky-wave antenna arrays
(1998-02-01)
Wang, CJ
;
Wu, JJ
;
Jou, CF
;
傳播研究所
;
Institute of Communication Studies
X-band active beam-scanning leaky-wave antenna arrays, including 1 X 1, 1 X 2 and 1 X 4 prototypes, have been demonstrated. These antennas integrated one or several microstrip leaky-wave antenna elements with a single varactor-tuned HEMT VCO as an active source. Measured results on experimental antennas indicate that the beam scanning angle of the 1 X 1 antenna close to 40(0) can be achieved and the scanning range of 1 X 2 and 1 X 4 antenna arrays are both close to 32(0), Furthermore, reflected wave due to the open end of each leaky-wave antenna element has been suppressed by the symmetric configuration of this antenna array and the antenna efficiency increases. When comparing with the measured radiation pattern of the single element antenna, we found that the 1 X 2 and 1 X 4 antenna arrays can effectively suppress the reflected power by more than 5.5 dB and 10.5 dB, respectively, at 10.2GHz. The power gain are more than 2 dB and 3.16 dB higher than the single element antenna with a measured EIRP of 18.67 dBm.
An active frequency-tuned beam-scanning leaky-wave antenna
(1998-01-01)
Hu, CC
;
Wu, JJ
;
Jou, CF
;
交大名義發表
;
傳播研究所
A frequency-tuned beam-scanning antenna is developed, which integrated a microstrip leaky-wave antenna with a varactor-tuned HEMT VCO as the source. The microstrip leaky-wave antenna is operated in the first higher mode. To excite the first higher mode, microstrip leaky-wave antenna is fed asymmetrically. The dominant mode excitation has been successfully suppressed by adding a sequence of covered wire in the center of the microstrip leaky-wave antenna. The HEMT oscillator frequency is controlled by tuning the varactor dc bias, and the beam scanning is demonstrated. The measured scanning angle agrees well with the prediction; it is close to 30 degrees as the VCO frequency is tuned from 8.06 to 9 GHz. (C) 1998 John Wiley & Sons, Inc.
An active microstrip antenna for satellite communication
(2000)
Wang, CJ
;
Jou, CF
;
Wu, JJ
;
Peng, ST
;
傳播研究所
An active microstrip antenna for the satellite communication is developed in this paper. A varactor-tuned oscillator HEMT VCO, an active source, integrates with an X-band two-terminal asymmetrically feeding microstrip leaky-wave antenna on the same plane. This approach creates a dual-beam radiation pattern and has the advantages of multi-direction and suppression of the reflected wave caused by the open end of the radiating element, as compared to a traditionally single-terminal feeding leaky-wave antenna. Measured results on the experimental antenna show that the total scanning angle of two beams of this antenna configuration is approximately 44 degrees. The maximum Effective Isotropic Radiated Power (EIRP) are close to 17.5 dBm for the right beam and 16.67 dBm for the left beam at 10.4 GHz, and the power difference between the two beams is less than 1 dB. An asymmetrically beam-scanning leaky-wave antenna is also shown in this presentation.