Ferrite LTCC-Based Antennas for Tunable SoP Applications

Design and Fabrication of a Frequency and Polarization Reconfigurable Microwave Antenna on a Printed Partially Magnetized Ferrite Substrate

“…For example, at 2.4 GHz and 4 GHz, the loss tangent values are 0.13 and 0.015 respectively. This is due to the low field losses of the magnetic material in the absence of the magnetic bias [21]. However, the loss tangent value at frequencies above fm is in the acceptable range.…”

“…Magnetization frequency is important as the ferrites do not show any low-field losses after this frequency [9]. It is recommended that the center frequency of a microwave device should be higher than the magnetization frequency of the medium to avoid any low field losses [21]. In order to estimate the loss of the ink, it is characterized for its linewidth (H =100 Oe at 3 GHz) using a half wavelength micrsotrip line resonator fabricated on Duroid 5880 board [22].…”

A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

“…The stack is made of ESL-40012 ferrite tape system [20]. This tape has a r ≈ 14.6, tan δ ≈ 5 × 10 −3 and a saturation magnetization (4πM s ) of 4000 Gauss that results in a magnetization frequency (f m ) of about 11.2 GHz [17]. The material is operated in the partially magnetized state (0 ≤ M ≤ M s ) to minimize the bias field required.…”

Design strategy for a tunable antenna on a partially magnetized ferrite LTCC substrate

“…The use of external magnets creates large demagnetization effects at the boundary, rendering the design inefficient. Alternately, a multilayer substrate such as ferrite LTCC (Low Temperature Co-fired Ceramic) with embedded windings can be employed to bias the ferrite, thus negating the need for large and inefficient external magnets [2]. Further reduction in the applied bias fields is possible, if the antenna is tuned in the partially magnetized state of the ferrite substrate.…”