Types Of Diplexers Research Articles

Development of a new wideband heterodyne receiver system for the Osaka 1.85 m mm–submm telescope: Receiver development and the first light of simultaneous observations in 230 GHz and 345 GHz bands with an SIS-mixer with 4–21 GHz IF output

Abstract We have developed a wideband receiver system for simultaneous observations in CO lines of J = 2–1 and J = 3–2 transitions using the Osaka 1.85 m mm–submm telescope. As a frequency separation system, we developed multiplexers that connect three types of diplexers, each consisting of branch-line couplers and high-pass filters. The radio frequency (RF) signal is eventually distributed into four frequency bands, each of which is fed to a superconductor–insulator–superconductor (SIS) mixer. The RF signal from the horn is divided into two frequency bands by a wideband diplexer with a fractional bandwidth of $56\%$, and then each frequency band is further divided into two bands by each diplexer. The developed multiplexers were designed, fabricated, and characterized using a vector network analyzer. The measurement results showed good agreement with the simulation. The receiver noise temperature was measured by connecting the SIS-mixers, one of which has a wideband 4–21 GHz intermediate frequency (IF) output. The receiver noise temperatures were measured to be ∼70 K in the 220 GHz band, ∼100 K in the 230 GHz band, 110–175 K in the 330 GHz band, and 150–250 K in the 345 GHz band. This receiver system has been installed on the 1.85 m telescope at the Nobeyama Radio Observatory. We succeeded in simultaneous observations of six CO isotopologue lines with the transitions of J = 2–1 and J = 3–2 toward the Orion KL as well as on-the-fly mappings toward the Orion KL and W 51.

Review on Technologies used to Design RF Diplexers

In this review paper we present the recent progress in the design of RF diplexers It is known that diplexers play an important role in many modern telecommunication systems In this context several types of diplexers have been proposed in literature This review is particularly interested in working principle and diplexers role in wireless communication systems It also discusses the main features of a diplexer and a general comparison between the various technologies used to design the diplexer circuits

Design and implementation of a narrow-band superconducting X-band diplexer with high isolation

This paper presents a high performance X-band diplexer with a 65MHz bandwidth operating at central frequencies of 9.90 and 10.02GHz. Outstanding six-pole channel filters with a high out-of-band rejection are realized by utilizing a double-folded resonator and suppressing nonadjacent couplings on the basis of coupling analysis to improve the filtering performance of the diplexer. Two types of diplexers are compared in terms of isolation and packaging box's influence. The T-type topology is better than Y-type, and its isolation exceeds 70dB. Moreover, the return loss and insertion loss is better than 13dB and 0.4dB respectively. The measurements agree well with the simulations, demonstrating that a high performance X-band diplexer with a compact size can be realized by HTS film apart from waveguide structure.

Wide-band low-loss high-isolation microstrip periodic-stub diplexer for multiple-frequency applications

This paper introduces a three-port microstrip multifrequency diplexer used in a phased-array transceiver system that employs band-stop filters with open-circuited stubs for band selection and separation. The diplexer is designed to take 10, 12, 19, and 21 GHz into port 1 and to separate 10 and 19 GHz to port 2 and 12 and 21 GHz to part 3 with minimal dispersion. The insertion loss for each frequency varies from 0.4 to 3.4 db and the return loss is better than 10 dB. The isolation between channels at the four frequencies is greater than 50 dB. Each passband created between adjacent stopbands has a bandwidth over 1 GHz. The microstrip diplexer is designed using periodic stubs that collectively have the advantages of low insertion loss, high isolation and rejection, wide-band performance on each channel, and easy fabrication. This type of diplexer has many applications in multifrequency transceivers for communication systems.

Characteristics of new types of quasi‐optical diplexers

AbstractThe quasi‐optical diplexer presently is considered to be as interesting as a special‐purpose filter, which divides or mixes the electromagnetic waves above microwave frequency in free space. This paper reports on the new types of diplexers: the gridded square, gridded square frame and gridded double square frame types. The feature of these new types is that various frequency characteristics from broad to sharp, can be realized by adjusting independent parameters, and the symmetry or linearity around the resonant frequency can also be realized. This has been difficult in past diplexers. By a systematic experiment, the frequency characteristics of the new types of diplexers are examined. Empirical formulas are derived for the resonant and anti‐resonant frequencies, as well as fractional bandwidth as functions of dimensional parameters. Based on these expressions of the characteristics, the design protocols are presented to meet various requirements. Although there still exists an error in the sense of reproducibility, which is less than 15 percent, the design for the proposed diplexers is established. Thus, the diplexers proposed in this paper have desirable characteristics, which have not been observed in the past. With the detailed design formulas for a wide range of frequencies from roughly 1 to 100 GHz, the diplexers can cope with various requirements, and a diversity of applications can be expected.

Quasi-Optical Polarization Diplexing of Microwaves

The feasibility of a microwave quasi-optical polarization diplexer has been demonstrated using photo-etched copper strips with thin mylar backing as a practical example. The insertion losses of the principal polarization and the cross polarization have been calculated and measured. The conducting strips must be aligned in a preferred direction, namely, perpendicular to the plane of incidence, to minimize cross-polarized radiation, whereas orientation of the plane of the grid with respect to the beam direction is not restricted. The measured cross-polarized radiation agrees with predictions from simple theoretical models of a magnetic current sheet for the transmission mode and an electric current sheet for the reflection mode. This type of diplexer has been successfully employed in studying the polarization properties of the 20-GHz signal from the ATS-6 satellite.

Walk-Off Effects in Fabry-Perot Diplexers

Fabry-Perot (FP) resonators working under oblique incidence can be used in the millimeter and far infrared bands as diplexers or channel dropping filters. The response of two-grid Fabry-Perot resonators under Gaussian beam excitation is evaluated by adding the fields of the successive passes of the beam. The results coincide with those obtained from a plane wave expansion of the incident field. Closed form expressions are obtained for the losses due to diffraction walk-off, geometrical walk-off, and mismatch. Excellent agreement is obtained with experiments in the 70-80-GHz band. For a 1-GHz-bandwidth filter, working at an incidence angle of 15 degrees, and an incident beam waist radius of 40 mm, the transmission loss at resonance does not exceed 1 dB. The reflection loss off-resonance is about 0.1 dB. This type of diplexer is particularly useful when used in conjunction with quasioptical guiding systems.