• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.8
• /
• pp.1415-1423
• /
• 2007

Total efficiency of transmitter system was improved by developing combinational 2-Way Isohybrid for GSM1900 base station in this paper. The size of product was decreased and the characteristics were stabilized. The isohybrid transmitter combiner of chip coupler type and hybrid coupler type were designed and fabricated. Insertion loss for chip coupler type isohybrid was $3.17\;dB{\sim}3.47\;dB$. On the other hand, insertion loss for hybrid coupler type was $3.17\;dB{\sim}3.42\;dB$. Isolations between ANT and port were $24.23\;dB{\sim}29.98\;dB$ in case of chip coupler type Isohybrid and were $26.28\;dB{\sim}36.91\;dB$ in case of hybrid coupler type, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.8
• /
• pp.862-877
• /
• 2008

In this paper, two types of wideband 3-dB ring hybrids are compared and discussed to show the ring hybrid with a set of coupled-line sections better. However, the better one still has a realization problem that perfect matching can be achieved only with -3 dB coupling power. To solve the problem, a set of coupled-line sections with two shorts is synthesized using one- and two-port equivalent circuits and design equations are derived to have perfect matching, regardless of the coupling power. Based on the design equations, a modified ${\Pi}-type$ of transmission-line equivalent circuit is newly suggested. It consists of coupled-line sections with two shorts and two open stubs and can be used to reduce a transmission-line section, especially when its electrical length is greater than ${\pi}$. Therefore, the $3\;{\lambda}/4$ transmission-line section of a conventional ring hybrid can be reduced to less than ${\pi}/2$. To verify the modified ${\Pi}-type$ of transmission- line equivalent circuit, two kinds of simulations are carried out; one is fixing the electrical length of the coupled-line sections and the other fixing its coupling coefficient. The simulation results show that the bandwidths of resulting small transmission lines are strongly dependent on the coupling power. Using modified and conventional ${\Pi}-types$ of transmission-line equivalent circuits, a small ring hybrid is built and named a compact wideband coupled-line ring hybrid, due to the fact that a set of coupled-line sections is included. One of compact ring hybrids is compared with a conventional ring hybrid and the compared results demonstrate that the bandwidth of a proposed compact ring hybrid is much wider, in spite of being more than three times smaller in size. To test the compact ring hybrids, a microstrip compact ring hybrid, whose total transmission-line length is $220^{\circ}$, is fabricated and measured. The measured power divisions($S_{21}$, $S_{41}$, $S_{23}$ and $S_{43}$) are -2.78 dB, -3.34 dB, -2.8 dB and -3.2 dB, respectively at a design center frequency of 2 GHz, matching and isolation less than -20 dB in more than 20 % fractional bandwidth.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.42 no.3 s.333
• /
• pp.33-38
• /
• 2005

In this paper, we have designed and fabricated a hybrid ring coupler to prove the fabrication possibility of various passive components, applying millimeter wave using newly proposed transmission lines, i.e. BAMLs. The characteristics of the fabricated hybrid ing coupler were a the S31(coupling) of 3.58 dB, the S21(thru) of 3.31 dB at the 60 GHz center frequency, the S11(return loss) over 16.17 dB, S41(isolation) over 55 dB at 61 GHz, and the phase difference between port 2 and port 3 of $180{\pm}loat$ 60GHz. In order to reduce the size of hybrid ring coupler, we designed the hybrid ring coupler which inserts a slow wave structure. With this structure, we were able to reduce the hybrid ring coupler by $33\%$ area.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.3
• /
• pp.25-32
• /
• 1992

In UHF, VHF new design method of samll-sized 3-dB 0$^{\circ}$/180$^{\circ}$ ring hybrid terminated arbitrary impedance using both lumped elements and distributed elements is presented. At the center frequency of 900 MHz, 3-dB 0$^{\circ}$/180$^{\circ}$ ring hybrid terminated arbitrary impedance is designed, analyzed and tested. Good agreements are obtained between measured and theoretical modeling results, and at the same time, the circuit area of hybrid fabricated with two dimensional parallel coupled line, distributed elements and lumped elements is reduced by more than 70% compared with only distribyted-type circuits.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.10 no.6
• /
• pp.317-326
• /
• 1985

A broad-band design method of a lumped-element 3dB quadrature hybrid without magnetic coupling is proposed and discussed, where techniques of cascading fundamental hybrids via second-order delay equalizers and adding matching sections are adopted. It is shown that the designed broad-band lumped-element 3dB quadrature hybrid can be easily constructed and its bandwidth reaches up to 54%. Furthermore, the esperiments have been carried out, the results of which agree with the theoretical ones, and hence, the validity of the broad-band design method proposed here was confirmed.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.6
• /
• pp.18-25
• /
• 1994

If a 4-port network is terminated by arbitrary impedances, there are great advantageges in composing systems with it. The distributed 3-dB $O^{\circ}$/180$^{\circ}$ hybrid with the impedances asymmetrically terminated is presented. In the band of UHF and VHF. on the basis of it , the new design method of small sized- hybrid using both lumped and distributed elements is also presented and analyzed At the center frequency of 900MHz. 3-dB $O^{\circ}$/180$^{\circ}$hybrid on the RT/Duroid substrate of ${\varepsilon}_{r}$=2.2, h=0.76mm is design and tested. Agreements are obtained between measured and theoretical results and at the same time the occupied area of it is reduced more than 70% compared with only distributed-type circuits.

• Journal of information and communication convergence engineering
• /
• v.14 no.4
• /
• pp.246-251
• /
• 2016

In this study, we developed a reduced 94 GHz hybrid ring coupler on a GaAs substrate in order to demonstrate the possibility of the integration of various passive components and MMICs in the millimeter-wave range. To reduce the size of the hybrid ring coupler, we used multiple open stubs on the inside of the ring structure. The chip size of the reduced hybrid ring coupler with multiple open stubs was decreased by 62% compared with the area of the hybrid ring coupler without open stubs. Performance in terms of the loss, isolation, and phase difference characteristics exhibited no significant change after the use of the multiple open stubs on the inside of the ring structure. The reduced hybrid ring coupler showed excellent coupling loss of $3.87{\pm}0.33dB$ and transmission loss of $3.77{\pm}0.72dB$ in the measured frequency range of 90-100 GHz. The isolation and reflection were -48 dB and -32 dB at 94 GHz, respectively. The phase differences between two output ports were $180^{\circ}{\pm}1^{\circ}$ at 94 GHz.

• Journal of Advanced Navigation Technology
• /
• v.14 no.6
• /
• pp.909-915
• /
• 2010

In this paper, the unequal power divider based on CRLH (Composite Right/Left-Handed) transmission line with dual-band characteristic is proposed. They consist of dual-band branch line hybrid coupler, the connection between input and isolation port of hybrid coupler and ${\lambda}/4$ impedance transformer. When the transmission line between input and isolation port of hybrid coupler is asymmetrical connected, the divider is obtained the output results of the equal phase and unequal power dividing ratio. The simulation results of the divider represent the power ratio of 0 dB ~ 20 dB. To validate a function of divider, the hybrid coupler and transformer with 880 MHz and 1850 MHz is implemented. As a result, the proposed unequal divider obtains the power ratio of 3.2 dB ~ 8.8 dB at 880 MHz and 2.5 dB ~ 14.0 dB at 1850 MHz.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.28A no.1
• /
• pp.15-22
• /
• 1991

New design method of small-sized 3-dB $0^{\circ}/180^{\circ}$ ring hybrid and Wilkinson power divider using both lumped elements and distributed elements are presented. At the center frequency of 900 MHz 3-dB $0^{\circ}/180^{\circ}$ ring hybrid and Wikinson power divider are designed and tested. Good agreements are obtained between measured and theoretical modeling results, and at the same time the circuit area is reduced by more than 70% compared with the discributed-type circuits.

• Journal of the Korean Institute of Navigation
• /
• v.10 no.1
• /
• pp.29-40
• /
• 1986

Abroad-band design method of a lumped-element 3 dB quadrature hybrid without magnetic coupling is proposed and discussed, where techniques of cascading fundamental hybrids via second-order delay equializers and adding matching sections are adopted. It is shown that the designed broad-band lumped-element 3 dB quadrature hybrid can be easily constructed and its bandwidth reaches up to 54%. Furthermore, the experiments have been carried out, the results of which agree with the theoretical ones, and hence, the validity of the broad-band design method proposed here was confirmed.