Izvorni znanstveni članak
https://doi.org/10.24138/jcomss-2025-0217
Novel Four-Port Diplexer–Antenna System with Simultaneous Isolation Enhancement and Impedance Control
Saad Wasmi Osman Luhaib
; University of Mosul, Mosul, Iraq
*
Farhad E. Mahmood
; University of Mosul, Mosul, Iraq
Shamil H. Hussein
; University of Mosul, Mosul, Iraq
* Dopisni autor.
Sažetak
This paper presents the design and simulation-based
performance evaluation of a novel four-port diplexer–antenna
system that simultaneously achieves high transmit/receive isolation
and robust impedance control. Two compact parallel-coupled
microstrip bandpass filters operating at 2.0 GHz (Rx) and 2.4
GHz (Tx) were synthesized using Chebyshev low-pass prototypes
and umerically modeled on a Rogers substrate RO3006 (ϵr = 6.5,
h = 1.27 mm, tanδ = 0.002). The filters were integrated into a fourport
diplexer topology employing a 180o phase-inversion path to
exploit amplitude-and-phase cancellation, thereby reducing filter
order and insertion loss while enhancing port-to-port isolation.
Full-wave simulations and parametric analyses reveal that the
proposed design yields an isolation of 50 dB at 2 GHz and
78.5 dB at 2.4 GHz, representing a substantial improvement
over conventional single-filter configurations. Furthermore, the
system’s isolation performance was evaluated under realistic antenna
impedance variations; results show the design retains high
isolation despite shifts in both the real and imaginary components
of the antenna impedance, with the Tx port demonstrating
particularly strong resilience near the matched condition. These
findings verify that the co-optimized diplexer–antenna approach
effectively mitigates impedance mismatch effects, offering a
compact and low-loss solution for modern multi-band wireless
front ends requiring stringent Tx/Rx isolation.
Ključne riječi
Four-Port Diplexer; High Isolation; Impedance Control; Communication Systems
Hrčak ID:
348546
URI
Datum izdavanja:
31.3.2026.
Posjeta: 0 *