Methodology to develop a low-loss dual-band stripline circulator

Ferrite-Based Multiport Circulators With RF Co-Designed Bandpass Filtering Capabilities

“…The co-designed BPF and quasi-circulator in [54] exhibit similar performance with regard to IS; however, it consumes dc power and has only been demonstrated for a lower order transfer functions with up to two poles. When compared to ferrite-based circulators without filtering capabilities (see [9], [18], [22], [25], [27]), the proposed concept exhibits similar size and comparable IS. When doing a direct comparison to the RF co-designed ferritebased BPFC [28], this work presents higher order transfer functions (>3 poles) with similar IS levels (∼30 dB).…”

“…N ON-RECIPROCAL RF components, such as isolators or circulators, are of increasing importance in emerging RF front-ends as they serve two primary roles: 1) they separate the transmitted from the received RF signals in full-duplex RF transceivers [1], [2], [3] and 2) they protect sensitive RF devices against unwanted reflections [4]. One of the main approaches to realize isolators/circulators is to incorporate ferromagnetic materials within the volume of a two-port or a three-port microwave network and achieve non-reciprocity by applying magnetic biasing [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29]. Notable demonstrations of ferrite-based devices include: 1) waveguide-type isolators/circulators [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], where a ferrite slab is integrated within a 3-D waveguide or a Y-junction; 2) stripline-based [15], [16], [17], [18], <...…”

“…One of the main approaches to realize isolators/circulators is to incorporate ferromagnetic materials within the volume of a two-port or a three-port microwave network and achieve non-reciprocity by applying magnetic biasing [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29]. Notable demonstrations of ferrite-based devices include: 1) waveguide-type isolators/circulators [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], where a ferrite slab is integrated within a 3-D waveguide or a Y-junction; 2) stripline-based [15], [16], [17], [18], [19] and microstrip-based [20], [21], [22], [23] isolators/circulators; 3) four-port phase shifters, couplers, and circulators in [24],…”

“…Waveguide-based isolators/circulators exhibit low insertion loss (IL) (<1 dB in [7] and [9]) and can be used in high power and higher frequency (i.e., X-band in [6], [7], [8], [9], [12], and [14]) applications; however, they are really large in size. The stripline-based isolators/circulators are smaller and can also be designed for dual-band functionality [16], [18]. Nevertheless, they require two ferrite disks that increase their volume.…”