A miniaturized antenna suitable for micro medical devices and other scenarios

Abstract

A miniaturized antenna suitable for micro-medical devices and other scenarios, a capsule-type medical device, and a micro-antenna. The antenna includes a first zigzag portion extending from a first proximal end to a first distal end; a first straight portion extending from a first connection end to a first feeding end, the first connection end being connected to the first proximal end; a second zigzag portion extending from a second proximal end to a second distal end; a second straight portion extending from a second connection end to a second feeding end, the second connecting end being connected to the second proximal end; and a body portion, the first straight portion being connected to the second straight portion via the body portion, such that the first proximal end and the second proximal end are spaced apart.

Description

Technical Field

[0001] The present application relates to the field of medical devices and is also applicable to other scenarios where there is a demand for miniaturized complex input impedance antennas, and in particular to antennas suitable for miniature medical devices. Background Art

[0002] In the medical device field, capsule endoscopes have the advantages of being minimally invasive to the target patient and not requiring anesthetics, making them widely applicable. Capsule antennas are an essential component of capsule endoscopes. Chips suitable for capsules typically have complex input impedance. Under normal circumstances, antennas used in capsule endoscopes require additional impedance matching circuits to achieve impedance matching with the chip. Therefore, antennas with complex impedance that can be directly connected to the chip and achieve impedance matching have a clear advantage. However, for typical micro-antennas, the real and imaginary components of their input impedance are difficult to flexibly adjust over a wide range. Summary of the Invention

[0003] This article discloses a miniaturized antenna that provides a practical solution to the aforementioned technical challenges. This antenna is suitable for use in miniaturized medical devices. It is particularly well-suited for capsule-type medical devices (such as capsule endoscopes) and is also applicable to other scenarios requiring a miniaturized complex input impedance antenna.

[0004] In one aspect, this document discloses a miniaturized antenna suitable for use with a micromedical device. The miniaturized antenna includes: a first meandering portion extending from a first proximal end to a first distal end; a first straight portion extending from a first connection end to a first feeding end, the first connection end being connected to the first proximal end; a second meandering portion extending from a second proximal end to a second distal end; a second straight portion extending from a second connection end to a second feeding end, the second connection end being connected to the second proximal end; and a body portion, the first straight portion being connected to the second straight portion via the body portion, such that the first proximal end and the second proximal end are spaced apart. A first gap is formed between the first feeding end and the first distal end, the first gap having no conductive elements therein, thereby forming a capacitive coupling; and a second gap is formed between the second feeding end and the second distal end, the second gap having no conductive elements therein, thereby forming a capacitive coupling. The first feeding end and the second feeding end can receive differential feed signals.

[0005] Preferably, the first straight portion and the second straight portion extend substantially parallel to each other, wherein the first straight portion and the second straight portion define a first interval therebetween.

[0006] Optionally, the first meandering portion, the second meandering portion, the first feeding end, and the second feeding end are arranged on a first plane.

[0007] Optionally, the first meandering portion and the second meandering portion are arranged on a first plane, and the first feeding end and the second feeding end are arranged on a second plane spaced apart from the first plane.

[0008] Optionally, the first straight portion and the second straight portion are oriented to the symmetry axis of the antenna.

[0009] On the other hand, this article discloses a capsule-type medical device, which includes: a shell; a circuit arranged in the shell; and a miniaturized antenna of any of the above schemes, wherein the first feeding end and the second feeding end of the miniaturized antenna are respectively electrically coupled to the circuit.

[0010] Preferably, the first meandering portion and the second meandering portion of the miniaturized antenna are arranged on a first plane, and the first plane is spaced apart from the housing.

[0011] On the other hand, this article also discloses a miniature antenna, which includes: a ∏-matching element, the ∏-matching element including a pair of straight portions defining a first interval between each other; and a pair of meandering portions, wherein the meandering portions are respectively connected to the ∏-matching element, so that the real part and the imaginary part of the input impedance of the antenna are parameters independent of each other.

[0012] Preferably, gaps suitable for forming capacitive coupling are defined between distal ends of the meandering portions and the corresponding feeding ends of the straight portions, and the feeding ends of the straight portions of the Π-matching element can receive differential feeding signals.

[0013] Preferably, the dimensions of the Π-match are arranged to be adjusted in response to a target input impedance of the miniature antenna.

[0014] Optionally, the length of the straight portion is configured to be adjusted in response to an imaginary part of a target input impedance of the micro-antenna.

[0015] Optionally, the length of the meander is arranged to be adjusted in response to a real part of a target input impedance of the micro-antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a perspective view of a medical device according to one embodiment;

[0017] Figure 2 is a perspective view of an antenna in a medical device according to one embodiment;

[0018] Figure 3 is a top view of an antenna according to one embodiment;

[0019] Figure 4 Show Figure 3 Top view of antenna dimensions;

[0020] Figure 5 Show Figure 4 The antenna impedance response of the medium antenna changes due to the change of the antenna size s1;

[0021] Figure 6 Show Figure 4 The antenna impedance response of the medium antenna changes due to the change of the antenna size s2;

[0022] Figure 7 Show Figure 4 The antenna impedance response of the middle antenna changes due to the change of the antenna size g3;

[0023] Figure 8 is a top view of an antenna according to another embodiment;

[0024] Figure 9 is a top view of an antenna according to another embodiment;

[0025] Figure 10 is a top view of an antenna according to another embodiment;

[0026] Figure 11 is a top view of an antenna according to another embodiment;

[0027] Figure 12 is based on Figure 11 A perspective view of an antenna according to an embodiment;

[0028] Figure 13 is based on Figure 12 A perspective view of the bottom of the antenna along the AA perspective;

[0029] Figure 14 is a top view of an antenna according to another embodiment;

[0030] Figure 15 is a top view of an antenna according to another embodiment;

[0031] Figure 16 is based on Figure 3 An equivalent circuit diagram of an embodiment antenna; and

[0032] Figure 17 A simulation structure showing antenna return loss. DETAILED DESCRIPTION

[0033] It will be appreciated that, in addition to the described example embodiments, the components of the embodiments as generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the example embodiments illustrated in conjunction with the figures and the following more detailed description are merely representative of example embodiments and do not limit the scope of the claimed embodiments.

[0034] References throughout this specification to "one embodiment," "another embodiment," or "an embodiment" (or similar terms) mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment," etc., in various places throughout this specification are not necessarily referring to the same embodiment.

[0035] In addition, the described features, structures or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will appreciate that various embodiments can be put into practice without one or more specific details or by utilizing other methods, components, materials, etc. In other cases, some or all known structures, materials, or operations may not be shown or described in detail to avoid confusion.

[0036] The present disclosure provides a miniaturized antenna with a complex input impedance and flexible adjustment. The antenna is suitable for use in applications requiring miniature (miniaturized) complex input impedance antennas, such as medical devices, miniature medical detection devices, capsule medical devices, capsule endoscopes, biomedical electronic devices, consumer electronics, miniature wireless communication devices, and miniature detection devices.

[0037] Figure 1 A micro medical device and an antenna therein according to an embodiment of the present invention are shown. As an example, the medical device may be configured as a capsule-type medical device having an antenna 100, such as a capsule endoscope 10. The capsule endoscope 10 includes a shell 20, a circuit 30 arranged in the shell 20; and an antenna 100 provided on a substrate 40 and electrically coupled to the circuit 30. The antenna 100 may be a metal antenna 100, for example, made of a copper sheet. It is understandable that the shell also needs to accommodate other elements of the capsule endoscope, such as batteries, sensors, etc., so the space in which the antenna can be set is limited. As an example, the antenna 100 may be configured as a conformal antenna structure that can fit snugly against the shell. The antenna 100 according to an embodiment of the present invention occupies a small space, so it may also be configured as follows. Figure 2The planar structure shown is separated from the housing, resulting in relatively stable dielectric properties and greater reliability and durability. Antenna 100 can be disposed on substrate 40, and circuit 30 can be disposed on a circuit board. Contact pins 50 can be disposed between antenna 100 and circuit 30, extending through substrate 40 to form an electrical coupling between antenna 100 and circuit 30.

[0038] Reference Figure 3 In the illustrated embodiment, antenna 100 can be viewed as a structure symmetrical about an axis of symmetry 180. For ease of description, axis of symmetry 180 is oriented axially, with the axial direction being parallel to the first plane; the longitudinal direction refers to a direction perpendicular to the axial direction and parallel to the first plane. Antenna 100 includes a first meandering portion 120 and a second meandering portion 130 symmetrical thereto. Antenna 100 also includes a first straight portion 140 and a second straight portion 150 symmetrical thereto. The first meandering portion 120 extends from a first proximal end 112 to a first distal end 122. The second meandering portion 130 extends from a second proximal end 113 to a second distal end 132. The first straight portion 140 extends from a first connecting end 141 to a first feeding end 142, and the first connecting end 141 is connected to the first proximal end 112. The second straight portion 150 extends from a second connecting end 151 to a second feeding end 152, and the second connecting portion 151 is connected to the second proximal end 113. The first proximal end 112 can be said to be connected to the second proximal end 151 via the first connecting end 141, while the second proximal end 113 is connected to the first connecting end 141 via the second connecting end 151. The antenna 100 may further include a body 110, through which the first straight portion 140 is connected to the second straight portion 150, so that the first proximal end 112 and the second proximal end 113 are spaced apart. The body 100 may further include a first extension 114 and a second extension 115. The body 110 is connected to the first straight portion 140 and the second straight portion 150 via the first extension 114 and the second extension 115, respectively. The first connecting end 141 and the first extending body 114 are arranged parallel to each other along the axial direction and are spaced apart from each other. The second connecting end 151 and the second extending body 115 are arranged parallel to each other along the axial direction and are spaced apart from each other. The body 110 is disposed between the first connection end 141 and the second connection end 151. The first connection end 141 and the second connection end 151 are separated from each other and not directly connected. The first zigzag portion 120 and the second zigzag portion 130 are connected to each other only through the first connection end 141 of the first straight portion 140, the body 110, and the second connection end 151 of the second straight portion 150.

[0039] The first straight portion 140 and the second straight portion 150 extend substantially parallel to each other. According to one example, the first straight portion 140 and the second straight portion 150 are oriented with respect to the axis of symmetry 180 of the antenna 100. According to another example, the first straight portion 140 and the second straight portion 150 do not need to be oriented with respect to the axis of symmetry 180 of the antenna 100. The first straight portion 140 and the second straight portion 150 define a first gap 160 between each other. In this embodiment, the first gap 160 between the first straight portion 140 and the second straight portion 150 can be equidistant. Alternatively, in other embodiments, the first gap 160 between the first straight portion 140 and the second straight portion 150 can be unequally spaced. The first straight portion 140 extends axially from the first feeding end 142 to the first connecting end 141. Across from the first connecting end 141, the first straight portion 140 is connected to the first extension body 114. The first extension body 114 extends axially to the body 110. The second straight portion 150 extends axially from the second feeding end 152 to the second connecting end 151. The second straight portion 150 is connected to the second extension body 115 at a point separated from the second connecting end 151. The second extension body 115 extends axially to the body 110. The body 110 extends longitudinally in a direction substantially perpendicular to the axial direction, connecting the first extension body 114 and the second extension body 115. In other words, the longitudinal length of the body 110 defines the width of the first interval 160 between the first straight portion 140 and the second straight portion 150. For ease of explanation, the "Π-matching member" 190 herein refers to the combination of the first straight portion 140 (including the first connecting portion 141), the second straight portion 150 (including the second connecting portion 151), and the body 110 (including the first extension body 114 and the second extension body 115).

[0040] The first feeding end 142 and the second feeding end 152 can be electrically coupled to the circuit through the contact pins 54 and 55. For example, the first feeding end 142 and the second feeding end 152 can be connected to the balanced radio frequency (RF) output pins of the transceiver chip of the circuit 30. Figure 3As shown, a first gap 172 is formed between the first feeding end 142 and the first distal end 122. The first gap 172 lacks conductive elements, allowing the first gap 172 to form capacitive coupling. Similarly, a second gap 182 is formed between the second feeding end 152 and the second distal end 132. The second gap 182 lacks conductive elements, allowing the second gap 182 to form capacitive coupling. While the first distal end 122 forms a capacitive coupling with the corresponding first feeding end 142, the second distal end 132 also forms a capacitive coupling with the corresponding second feeding end 152. In other words, gaps suitable for forming capacitive coupling are defined between the distal ends of the meandering portions and the corresponding feeding ends of the straight portions. However, the arrangement, shape, and size of the first and second gaps can be adjusted according to practical application. For example, the first gap 172 can be configured as an equidistant curved gap; similarly, the second gap 182 can be configured as an equidistant curved gap. For another example, the first distal end 122 and the second distal end 132 are each configured to be concave, and the first feeding end 142 and the second feeding end 152 are each configured to be correspondingly convex, so that the first gap 172 and the second gap 182 each form an equidistant gap. It will be understood that the first gap 172 and the second gap 182 are not limited to equidistant gap shapes, and in other examples, they can also be zigzag shapes, interdigitated capacitor shapes, etc. In one example, the first meandering portion 120, the second meandering portion 130, the first feeding end 142, and the second feeding end 152 are arranged in a first plane. In another example, the first meandering portion 120 and the second meandering portion 130 are arranged in a first plane, and the first feeding end 142 and the second feeding end 152 are arranged in a second plane spaced apart from the first plane. In yet another example, the first meandering portion 120 and the second meandering portion 130 are arranged in a first plane that is spaced apart from the housing.

[0041] During operation, the first feeding end 142 / second feeding end 152 of the first straight portion 140 and the second straight portion 150 can receive the first electrical signal and the second electrical signal provided by the circuit 30 through the contact pins 54 / 55, respectively. The first electrical signal and the second electrical signal can be configured as differential feed signals, or the first electrical signal and the second electrical signal can be configured to have equal amplitudes and be 180 degrees out of phase with each other.

[0042] exist Figure 3In the illustrated embodiment, the first and second meandering portions 120, 130 have non-constant widths. For example, the first meandering portion 120 includes several narrower axial segments 124 / 134 and wider turn segments 126 / 136. A gap is formed between the first straight portion 140 and the distal axial segment 124a of the first meandering portion 120, with this gap extending to a first gap 172. Similarly, a gap is formed between the second straight portion 150 and the distal axial segment 134a of the second meandering portion 130, with this gap extending to a second gap 182. The first and second meandering portions 120, 130 may also be referred to as meander dipoles.

[0043] Figure 4 The following figure shows an example antenna structure dimension. In this example, an antenna with a diameter of 10 millimeters (mm) is suitable for use in a miniature antenna scenario. To ensure maximum power transfer between antenna 100 and circuit 30, the impedance of antenna 100 can be adjusted based on the output impedance of circuit 30. In one example, the miniature antenna includes: a pair of straight sections defining a first gap between them; a pair of meandering sections; and a ∏-matching element, wherein the straight sections and the meandering sections are respectively connected to the ∏-matching element, such that the real and imaginary components of the antenna's input impedance are independent parameters. The distal ends of the meandering sections of the antenna define gaps suitable for capacitive coupling with the feed ends of the corresponding straight sections. In one aspect, the dimensions of the ∏-matching element can be adjusted in response to the antenna's target input impedance. In another aspect, the length of the straight section can be adjusted in response to the imaginary component of the antenna's target input impedance. In another aspect, the length of the meandering section can be adjusted in response to the real component of the antenna's target input impedance. It will be appreciated that the real and imaginary components of the miniature antenna's impedance can be adjusted separately and independently of each other. This may include: selecting at least one of the size of the Π-matching member, the length of the straight portion, and the length of the curved portion to adjust the length. Figure 4 Examples of the dimensions of the Π-matching element may include, but are not limited to, the length of at least one of s2, w1, w2, and (g1+2w1). Examples of the length of the straight portion include the length of s1. Examples of the length of the meandering portion include the total length from the proximal end to the corresponding distal end. The target input impedance of the antenna may depend on the associated circuit to achieve impedance matching between the antenna and the associated circuit.

[0044] On the other hand, an embodiment includes making the target power transmission between the antenna 100 and the related circuits reach or approach it by setting the size of the Π-matching member 190. Figure 4In the figure, the body 110, the first extension body 114, the second extension body 115, the first connecting portion 141 and the second connecting portion 151 of the antenna 100 can be defined by antenna dimensions such as s2, w2, w3; the first straight portion 140 and the second straight portion 150 can be defined by antenna dimensions such as s1, w1, g1, dx, dy; and the first meandering portion 120 and the second meandering portion 130 can be defined by antenna dimensions such as l1, l2, l3, g2, g3, w3.

[0045] Figure 5 The antenna impedance response of antenna 100 is shown, which varies with changes in antenna dimension s1. As s1 (the length of the first straight portion or the second straight portion) changes, the antenna's resistance and reactance (impedance) vary, and the resonant frequency also changes accordingly. The antenna's impedance depends, at least in large part, on the length of the first straight portion or the second straight portion. The impedance matching between the antenna and the circuit depends, at least in large part, on the length of the first straight portion or the second straight portion. By adjusting the antenna structure dimensions, such as s1, the impedance matching between the antenna and the associated circuit can be effectively configured. Figure 6 The antenna impedance response of antenna 100 is shown, varying with changes in antenna dimension s2: As s2 (the axial length of the body, i.e., the axial length of the first or second extension) changes, the antenna's resistance and reactance (impedance) change by the same magnitude. In other words, the impedance matching between the antenna and the circuit is at least largely responsive to the length of the first or second straight portion. Figure 7 The antenna impedance response of the antenna 100 is shown, which varies due to changes in the antenna size g3: as g3 (the distance between the distal end and the corresponding feeding end, the width of the first gap or the second gap) changes, the impact on the resistance is greater than the impact on the reactance.

[0046] Therefore, if Figures 5 to 7 As shown, the impedance of the antenna changes gradually within the operating frequency range. The miniature antenna 100 can obtain a suitable corresponding antenna impedance by adjusting the antenna size (for example, changing the length of the first straight portion and the second straight portion, or the distance between the distal end and the feeding end) according to the working requirements or output impedance of the circuit 30. The impedance of the antenna changes gradually with the change of its operating frequency. It can be seen that compared with the traditional T-type matching antenna, the impedance of the antenna 100 changes more smoothly with frequency, which is more conducive to wide-band application scenarios. By adjusting the antenna size to adjust the antenna impedance, effective or appropriate power transmission can be ensured, and even the target power transmission can be achieved. The above antenna sizes are exemplary, so the impedance response of the antenna can also be changed by other antenna sizes.

[0047] Figure 8An antenna 200 according to another embodiment is shown. Antenna 200 includes a body 210; a first arm, such as a first meandering portion 220; a second arm, such as a second meandering portion 230; a first straight portion 240; and a second straight portion 250. The first meandering portion 220 and the second meandering portion 230 extend from the body 210 and are symmetrically arranged about a central axis 280 of the body 210, which defines an axial direction. The first straight portion 240 and the second straight portion 250 are joined to the body 210 and extend substantially parallel to the axial direction. Unlike the previous embodiment, the first meandering portion 220 and the second meandering portion 230 have a constant width, for example, the straight segments 224 / 234 and the turn segments 226 / 236 have substantially the same width.

[0048] The first straight portion 240 and the second straight portion 250 include respective feeding ends 242 / 252, each configured to receive respective first and second electrical signals from the circuit 30 via the contact pins 50. The first and second meandering portions 220 and 230 each include respective distal ends 222 / 232. The distal end 222 of the first meandering portion 220 forms a curved gap 272 with the respective feeding end 242. The distal end 232 of the second meandering portion 230 forms a curved gap 282 with the respective feeding end 252. Since there is no conductive element between each gap 272 / 282, capacitive coupling is formed between the distal ends 222 / 232 and the respective feeding end 242 / 252. The distal ends 222 / 232 are configured to be concave, and the feeding ends 242 / 252 are configured to be correspondingly convex. An equidistant gap 272 / 282 is formed between each pair of distal ends 222 / 232 and the corresponding feeding ends 242 / 252.

[0049] The antenna 200 includes a first meandering portion 220 extending from a first proximal end to a first distal end 222; a first straight portion 240 extending from a first connection end to a first feeding end 242, the first connection end being connected to the first proximal end; a second meandering portion 230 extending from a second proximal end to a second distal end 232; a second straight portion 250 extending from a second connection end to a second feeding end 252, the second connection end being connected to the second proximal end; and a body 210, the first straight portion 240 being connected to the second straight portion 250 via the body 210 so that the first proximal end and the second proximal end are spaced apart. The first straight portion 240 and the second straight portion 250 extend substantially parallel to each other and are oriented with respect to an axis of symmetry 280 of the antenna, with the first straight portion 240 and the second straight portion 250 defining a first gap therebetween.

[0050] Figure 9An antenna 300 according to another embodiment is shown. Antenna 300 includes a body 310; a first meandering portion 320; a second meandering portion 330; a first straight portion 340; and a second straight portion 350. The first meandering portion 320 and the second meandering portion 330 extend from the body 310 and are symmetrically arranged about a central axis 380 of the body 310, which defines an axial direction. The first and second straight portions 340 and 350 are joined to the body 310 and extend substantially parallel to each other along the axial direction. The first and second straight portions 340 and 350 include respective feeding ends 342 and 352, each configured to receive respective first and second electrical signals from the circuit 30. The first and second meandering portions 320 and 330 each include respective distal ends 322 and 332. Unlike the previous embodiment, the feeding ends 342 and 352 are not concave. A gap is formed between the first straight portion 340 and the distal straight segment 324a of the first meandering portion 320, and a gap is formed between the second straight portion 350 and the distal straight end 334a of the second meandering portion 330. Therefore, a linear gap 372 is formed between the distal end 322 of the first meandering portion 320 and the corresponding feeding end 342. Similarly, a linear gap 382 is formed between the distal end 332 of the second meandering portion 330 and the corresponding feeding end 352. Since there is no conductive element between the gaps 372 / 382, capacitive coupling is formed between the distal ends 322 / 332 and the corresponding feeding ends 342 / 352.

[0051] The antenna 300 includes a first meandering portion 320 extending from a first proximal end to a first distal end 322; a first straight portion 340 extending from a first connection end to a first feeding end 342, the first connection end being connected to the first proximal end; a second meandering portion 330 extending from a second proximal end to a second distal end 332; a second straight portion 350 extending from a second connection end to a second feeding end 352, the second connection end being connected to the second proximal end; and a body 310, the first straight portion 340 being connected to the second straight portion 350 via the body 310 so that the first proximal end and the second proximal end are spaced apart. The first straight portion 340 and the second straight portion 350 extend substantially parallel to each other and are oriented with respect to the antenna's axis of symmetry 380, with the first straight portion 340 and the second straight portion 350 defining a first gap therebetween.

[0052] Figure 10An antenna 400 according to another embodiment is shown. Antenna 400 includes a body 410; a first meandering portion 420; a second meandering portion 430; a first straight portion 440; and a second straight portion 450. The first meandering portion 420 and the second meandering portion 430 extend from the body 410 and are symmetrically arranged about a central axis 480 of the body 410, which defines an axial direction. The first and second straight portions 440, 450 are joined to the body 410 and extend substantially parallel to the axial direction. Unlike the previous embodiment, the first and second straight portions 440, 450 extend to approximately the center of the antenna. The first and second straight portions 440, 450 include respective feed ends 442 / 452 configured to receive respective first and second electrical signals from the circuit 30. The first and second meandering portions 420, 430 each include respective distal ends 422 / 432. The distal end 422 of the first meandering portion 420 forms a gap 472 with the corresponding feeding end 442. The distal end 432 of the second meandering portion 430 forms a gap 482 with the corresponding feeding end 452. Since there is no conductive element between each gap 472 / 482, the distal end 422 / 432 forms a capacitive coupling with the corresponding feeding end 442 / 452.

[0053] Antenna 400 includes a first meandering portion 420 extending from a first proximal end to a first distal end 422; a first straight portion 440 extending from a first connection end to a first feeding end 442, the first connection end being connected to the first proximal end; a second meandering portion 430 extending from a second proximal end to a second distal end 432; a second straight portion 450 extending from a second connection end to a second feeding end 452, the second connection end being connected to the second proximal end; and a body 410, the first straight portion 440 being connected to the second straight portion 450 via the body 410, such that the first proximal end and the second proximal end are spaced apart. The first straight portion 440 and the second straight portion 450 extend substantially parallel to each other and are oriented with respect to an axis of symmetry 480 of the antenna, with the first straight portion 440 and the second straight portion 450 defining a first gap therebetween.

[0054] Figures 11 to 13An antenna 500 according to another embodiment is shown. Antenna 500 includes a body 510; a first meandering portion 520; a second meandering portion 530; a first straight portion 540a; and a second straight portion 550a. The first meandering portion 520 and the second meandering portion 530 extend from the body 510 and are symmetrically arranged about a central axis 580 of the body 510, which defines an axial direction. The first straight portion 540a and the second straight portion 550a are joined to the body 510 and extend substantially parallel to the axial direction. Antenna 500 is provided in a planar form, defining a first plane 60. Unlike the previous embodiment, antenna 500 further includes first and second straight portion extensions 540b, 550b, respectively, electrically coupled to the first and second straight portions 540a, 550a. Optionally, conductive legs 560 are provided between the first and second linear extensions 540b, 550b of the first and second linear extensions 540a, 550a, respectively. The first and second linear extensions 540b, 550b are disposed on a second plane 70 parallel to and spaced apart from the first plane 60. The first and second linear extensions 540b, 550b include respective feeding ends 542 / 552 configured to receive respective first and second electrical signals from the circuit 30. The first and second meandering portions 520, 530 each include respective distal ends 522 / 532. The distal end 522 of the first meandering portion 520 on the first plane 60 forms a gap 572 with the corresponding feeding end 542 on the second plane 70. The distal end 532 of the second meandering portion 530 on the first plane 60 forms a gap 582 with the corresponding feeding end 552 on the second plane 70. There is no conductive element between the gaps 572 / 582 , so the distal ends 522 / 532 form capacitive coupling with the corresponding feeding ends 542 / 552 .

[0055] Antenna 500 includes a first meandering portion 520 extending from a first proximal end to a first distal end 522; a first straight portion 540 extending from a first connection end to a first feeding end 542, the first connection end being connected to the first proximal end; a second meandering portion 530 extending from a second proximal end to a second distal end 532; a second straight portion 550 extending from a second connection end to a second feeding end 552, the second connection end being connected to the second proximal end; and a body 510, the first straight portion 540 being connected to the second straight portion 550 via the body 510, such that the first proximal end and the second proximal end are spaced apart. The first straight portion 540 and the second straight portion 550 extend substantially parallel to each other and are oriented with respect to an axis of symmetry 580 of the antenna, wherein the first straight portion 540 and the second straight portion 550 define a first gap between each other. The first meandering portion 520 and the second meandering portion 530 are arranged on a first plane 60 , and the first feeding end 542 and the second feeding end 552 are arranged on a second plane 70 spaced apart from the first plane.

[0056] Figure 14 An antenna 600 according to one embodiment is shown. Antenna 600 includes a body 610; a first meandering portion 620; a second meandering portion 630; a first straight portion 640; and a second straight portion 650. The first meandering portion 620 and the second meandering portion 630 extend from the body 610 and are symmetrically arranged about a central axis 680 of the body 610. The central axis 680 defines an axial direction. In this embodiment, the first straight portion 640 and the second straight portion 650 are joined to the body 610 and extend slightly parallel to each other along the axial direction 680. A first gap 660 is defined between the first straight portion 640 and the second straight portion 650.

[0057] The first straight portion 640 and the second straight portion 650 also include corresponding convex feeding ends 642 / 652, each configured to receive a corresponding first electrical signal and a corresponding second electrical signal. As an example, the first meandering portion 620 and the second meandering portion 630 each include a corresponding concave distal end 622 / 632. The distal end 622 of the first meandering portion 620 forms a non-equidistant gap 672 with the corresponding feeding end 642. Similarly, the distal end 632 of the second meandering portion 630 forms a non-equidistant gap 682 with the corresponding feeding end 652. Since there is no conductive element between each gap 672 / 682, the distal ends 622 / 632 form a capacitive coupling with the corresponding feeding end 642 / 652.

[0058] The antenna 600 includes a first meandering portion 620, which extends from a first proximal end 612 to a first distal end 622; a first straight portion 640, which extends from a first connecting end 641 to a first feeding end 642, and the first connecting end 641 is connected to the first proximal end 612; a second meandering portion 630, which extends from a second proximal end 613 to a second distal end 632; a second straight portion 650, which extends from a second connecting end 651 to a second feeding end 652, and the second connecting end 651 is connected to the second proximal end 613; and a body 610, wherein the first straight portion 640 is connected to the second straight portion 650 through the body 610, so that the first proximal end 612 and the second proximal end 613 are separated. The first straight portion 640 and the second straight portion 650 extend substantially parallel to each other and are oriented to the symmetry axis 680 of the antenna, wherein the first straight portion 640 and the second straight portion 650 define a first gap 660 therebetween.

[0059] Preferably, if Figure 15 As shown, antenna 600 may further include first and second linear extensions 640b, 650b, electrically coupled to first and second feeding ends 642, 652, respectively. The first and second linear portions 640, 650 are disposed in a first plane. A conductive foot 670 is included between the first and second linear extensions 640b, 650b, respectively, of the first and second linear portions 640, 650. The first and second linear extensions 640b, 650b are disposed in a second plane parallel to and spaced apart from the first plane. The first and second linear extensions 640b, 650b include respective feeding ends 644 / 654, each configured to receive respective first and second electrical signals from a circuit. The first and second meandering portions 620, 630 each include respective distal ends 624 / 634. The distal end 624 of the first meandering portion 620 on the first plane forms a gap 674 with the corresponding feeding terminal 644 on the second plane. The distal end 634 of the second meandering portion 630 on the first plane forms a gap 684 with the corresponding feeding terminal 654 on the second plane. Since there is no conductive element between each gap 674 / 684, the distal end 674 / 684 forms a capacitive coupling with the corresponding feeding terminal 644 / 654.

[0060] Figure 16 Show this Figure 3 FIG1 is an equivalent circuit diagram 1500 of antenna 100, including an equivalent circuit 1510 of Π-matching element 190 and an equivalent circuit 1520 of meandering dipoles 120 and 130. The physical structure and dimensions of Π-matching element 190 allow the reactance and resistance of the antenna to be roughly controlled or customized. Figure 15L2 and R2 are equivalent to the reactance and resistance contributed by the first straight portion 140 and the second straight portion 150. When the resistance value of R2 is relatively small, the impedance matching or regulation of the antenna can be performed by setting the length of the first straight portion 140 or the second straight portion 150. It can be understood that the first straight portion 140 is symmetrical to the second straight portion 150, and the length of the first straight portion is equal to the length of the second straight portion 150, that is, s1. In addition to s1, other antenna structure dimensions can also be selected as parameters for formulating or regulating the antenna impedance. For example, the capacitance of c5 is set by the first gap and the second gap. It can be understood that Figure 15 Can also be combined Figures 8 to 14 The total length from the bent portion to the distal end is also a determining factor.

[0061] Resistance and reactance can be formulated roughly independently of each other, so the formulation of the antenna input impedance can be simplified. According to one example, the reactance of the antenna can be adjusted by formulating the value of the s1 parameter (i.e., formulating the lengths of the first straight portion and the second straight portion), while keeping the other structural dimensions of the antenna 100 unchanged. According to another example, any one or more of the following antenna structural parameters can be selected for formulation or adjustment: s1, s2, w2, g3, the length of the meandering portion, etc. This not only simplifies the impedance matching between the antenna and any circuit, but also obtains a wider tuning range of the input impedance. Therefore, according to an embodiment of the present invention, impedance matching between the antenna and the relevant circuit can be achieved without adding a special matching circuit.

[0062] Figure 17 Figure 2 shows simulation results of antenna return loss over a commonly used frequency range. A1 is the result obtained using an antenna according to an embodiment of the present invention. A2 and A3 are the results obtained using two different conventional T-matched antenna structures. Clearly, within the same frequency range, the antenna according to an embodiment of the present invention has a wider bandwidth and lower return loss.

[0063] As used herein, the singular "a" and "an" may be construed as including the plural "one or more" unless expressly stated otherwise.

[0064] This disclosure is for purposes of illustration and description and is not intended to be exhaustive or limiting. Many modifications and variations will be readily apparent to those skilled in the art. The exemplary embodiments selected and described herein are intended to illustrate principles and practical applications, so that those skilled in the art will understand the various modifications to which the various embodiments of this disclosure may be adapted to achieve the desired specific technical effects.

[0065] Therefore, although illustrative example embodiments have been described herein with reference to the accompanying drawings, it should be understood that this description is not limiting and that various other changes and modifications may be made by those skilled in the art without departing from the scope or inventive concepts and embodiments of the present disclosure.

Claims

1. A miniaturized antenna suitable for use in miniature medical devices and other scenarios where a miniaturized complex input impedance antenna is required, characterized in that: The miniaturized antenna includes: a first zigzag portion extending from a first proximal end to a first distal end; a first straight portion, the first straight portion extending from the first connecting end to the first feeding end, and the first connecting end being connected to the first proximal end; a second zigzag portion extending from the second proximal end to the second distal end; a second straight portion extending from the second connection end to the second feeding end; and the second connection end is connected to the second proximal end; and a body, wherein the first straight portion is connected to the second straight portion through the body, so that the first proximal end is spaced apart from the second proximal end. A first gap is formed between the first feeding end and the first distal end, and no conductive element is present in the first gap, so that the first gap forms a capacitive coupling; and a second gap is formed between the second feeding end and the second distal end, and no conductive element is present in the second gap, so that the second gap forms a capacitive coupling. The first feeding end and the second feeding end can receive differential feeding signals.

2. The miniaturized antenna according to claim 1, wherein: The first straight portion and the second straight portion extend substantially parallel to each other, wherein a first interval is defined between the first straight portion and the second straight portion.

3. The miniaturized antenna according to claim 1, wherein: The first meandering portion, the second meandering portion, the first feeding end, and the second feeding end are arranged on a first plane.

4. The miniaturized antenna according to claim 1, wherein: The first meandering portion and the second meandering portion are arranged on a first plane, and the first feeding end and the second feeding end are arranged on a second plane spaced apart from the first plane.

5. The miniaturized antenna according to claim 1, wherein: The first straight portion and the second straight portion are oriented to the symmetry axis of the antenna.

6. A capsule-type medical device, characterized in that: The capsule-type medical device comprises: case; an electric circuit disposed within the housing; and The miniaturized antenna according to any one of claims 1 to 5, wherein the first feeding end and the second feeding end of the miniaturized antenna are respectively electrically coupled to the circuit.

7. The capsule medical device according to claim 6, wherein: The first meandering portion and the second meandering portion of the miniaturized antenna are arranged on a first plane, and the first plane is spaced apart from the housing.

8. A miniature antenna, characterized in that: The miniature antenna includes: a Π-matching member comprising a pair of straight portions defining a first interval therebetween; and A pair of flexures, The meandering portions are respectively connected to the Π-matching elements, so that the real part and the imaginary part of the input impedance of the antenna are parameters independent of each other. A gap suitable for forming capacitive coupling is defined between the distal ends of the meandering portions and the corresponding feeding ends of the straight portions, and the feeding ends of the straight portions of the Π-matching element can receive differential feeding signals.

9. The miniature antenna according to claim 8, characterized in that: The dimensions of the Π-match are set to adjust in response to the target input impedance of the micro-antenna.

10. The miniature antenna according to claim 9, characterized in that: The length of the straight portion is set to be adjusted in response to the imaginary part of the target input impedance of the microantenna.

11. The miniature antenna according to claim 9, wherein: The length of the meander is configured to be adjusted in response to a real part of a target input impedance of the micro-antenna.

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