Magnet-less Non-Reciprocal Bandpass Filters With Tunable Center Frequency

Directivity Enhancement in Non-Reciprocal Bandpass Filters using an Evolutionary Algorithm

“…Almost comparable correlation of the simulated and measured results with the numerical modeling as shown in Fig. 3 [5], it suffers an IL of 3.7 dB which not only nullifies the competency of the power amplifier in the transmitter section, it also degrades the noise figure if implemented in the receiver section. The measured RL of the prototype NR-BPF is greater than 16 dB, thereby ensuring good matching with the source/load.…”

“…The first fabricated lumped realization of NR-BPF [4] achieves non-reciprocity at 200 MHz with manual optimization to choose the parameter values. Further, manual optimization has been carried out in the lumped realization of NR-BPF with tunable center frequency [5] and distributed realization of [6]. However, manual optimization results in a degraded insertion loss (IL) and return loss (RL) within the passbands.…”

MMIC GaAs Isolators and Quasi-Circulators With Co-Designed RF Filtering Functionality

“…Furthermore, when passive BPFs are realized with IC-based resonators, they exhibit high levels of IL (IL ∼ 4.5-9.3 dB in [14], [15]). To reduce the size of the non-reciprocal devices and BPFs, two major miniaturization approaches have been investigated: i) the integration of the non-reciprocal components into a chip using MMIC, CMOS, SiGe, technologies [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29] and ii) the RF co-design of the non-reciprocal components with the BPFs with or without ferrite-based elements [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44].…”

“…In yet another magnetless circuit-based design approach, spatiotemporally modulated (STM) switched capacitor arrays, transmission lines or resonator-arrays are employed within a three-port network to achieve non-reciprocity [46], [47], [48], [49]. Alternative integration schemes using PCB ( [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [48]) and CMOS based integration platforms ( [46], [47], [48], [49]) have been demonstrated. However, the operating principles of many of them have been demonstrated at frequencies <1.2 GHz (e.g., [32], [33], [34], [35], [36], [37], [40], [41], [48], [49]).…”

“…Alternative integration schemes using PCB ( [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [48]) and CMOS based integration platforms ( [46], [47], [48], [49]) have been demonstrated. However, the operating principles of many of them have been demonstrated at frequencies <1.2 GHz (e.g., [32], [33], [34], [35], [36], [37], [40], [41], [48], [49]). High-frequency implementations of STM-based circulators using CMOS technologies have also been shown to higher frequencies as for example at 6 GHz in [50], at 28 GHz in [51] and at 60 GHz in [52].…”