WO2010139120A1

WO2010139120A1 - Multi-band monopole antennas with parasitic elements

Info

Publication number: WO2010139120A1
Application number: PCT/CN2009/072154
Authority: WO
Inventors: Anders Thornell-Pers; Yuantao Luan
Original assignee: Laird Technologies (Beijing) Co., Ltd.
Priority date: 2009-06-05
Filing date: 2009-06-05
Publication date: 2010-12-09

Abstract

Multi-band monopole antennas for wireless application devices are disclosed. An example antenna includes a monopole element for connection to a feed point, a low band parasitic element for connection to a ground, and a high band parasitic element for connection to the ground. The monopole element is configured to resonate in at least a first frequency range and a second frequency range. The low band parasitic element is adjacent at least part of the monopole element and the low band parasitic element is configured to increase a bandwidth of the first frequency range. The high band parasitic element is adjacent at least part of the monopole element and the high band parasitic element is configured to increase a bandwidth of the second frequency range.

Description

MULTI-BAND MQNQPQLE ANTENNAS WITH PARASITIC

ELEMENTS

FIELD

[0001] The present disclosure generally relates to multi-band monopole antennas for use with wireless application devices.

BACKGROUND

[0002] This section provides background information related to the present disclosure which is not necessarily prior art.

[0003] Wireless application devices, such as laptop computers, cellular phones, etc. are commonly used in wireless operations. And, such use is continuously increasing. Consequently, additional frequency bands are required to accommodate the increased use, and antennas capable of handling the additional different frequency bands are desired.

SUMMARY

[0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0005] According to various aspects, example embodiments are provided of antennas configured to be installed to wireless application devices. In one example embodiment, a multi-band monopole antenna generally includes a first resonant element for connection to a feed point, a second resonant element for connection to a ground, and a third resonant element for connection to the ground. The second resonant element is adjacent at least part of the first resonant element and the second resonant element is configured for electromagnetic coupling with the first resonant element. The third resonant element is adjacent at least part of the first resonant element and the third resonant element is configured for electromagnetic coupling with the first resonant element.

[0006] In another example embodiment, a multi-band monopole antenna generally includes a monopole element for connection to a feed point, a low band parasitic element for connection to a ground, and a high band parasitic element for connection to the ground. The monopole element is configured to resonate in at least a first frequency range and a second frequency range. The low band parasitic element is adjacent at least part of the monopole element and the low band parasitic element is configured to resonate to increase a bandwidth of the first frequency range. The high band parasitic element is adjacent at least part of the monopole element and the high band parasitic element is configured to resonate to increase a bandwidth of the second frequency range.

[0007] According to various aspects, example embodiments are provided of wireless application devices including a multi-band monopole antenna. In one example embodiment, a wireless application device generally includes a ground plane, a feed point for transmitting and receiving radio frequency signals, and a multi-band monopole antenna coupled to the ground plane and the feed point. The antenna includes a monopole element coupled to the feed point, a low band parasitic element coupled to the ground plane, and a high band parasitic element coupled to the ground plane. The monopole element is configured to resonate in at least a first frequency range and a second frequency range. The low band parasitic element is adjacent at least part of the monopole element and configured to resonate to increase a bandwidth of the first frequency range. The high band parasitic element is adjacent at least part of the monopole element and configured to resonate to increase a bandwidth of the second frequency range.

[0008] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

[0009] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0010] FIG. 1 is an isometric view of a portion of a ground plane and an example embodiment of a multi-band monopole antenna including one or more aspects of the present disclosure;

[0011] FIG. 2 is an isometric view of the antenna and ground plane of FIGl;

[0012] FIG. 3 another isometric view the antenna and ground plane portion of FIGl;

[0013] FIG. 4 is a schematic illustration of the antenna of FIG. 1 connected to a ground and a feed point; [0014] FIG. 5 is a line graph illustrating the S-parameter magnitude in decibels for the example antenna of FIG. 1 over a frequency bandwidth of about 500 megahertz to about 3000 megahertz;

[0015] FIG. 6 is a line graph illustrating the Voltage Standing Wave Ratio for the example antenna of FIG. 1 over a frequency bandwidth of about 0.5 gigahertz to about 3 gigahertz;

[0016] FIG. 7 is an S-parameter Smith chart for the antenna of FIG. 1 over a frequency bandwidth of about 0.5 gigahertz to about 1.5 gigahertz;

[0017] FIG. 8 is an S-parameter Smith chart for the antenna of FIG. 1 over a frequency bandwidth of about 1.5 gigahertz to about 3 gigahertz;

[0018] FIG. 9 is a schematic illustration of another example embodiment of a multi-band monopole antenna including one or more aspects of the present disclosure;

[0019] FIG. 10 is a schematic illustration of another example embodiment of a multi-band monopole antenna including one or more aspects of the present disclosure;

[0020] FIG. 11 is a schematic illustration of another example embodiment of a multi-band monopole antenna including one or more aspects of the present disclosure;

[0021] FIG. 12 is a schematic illustration of another example embodiment of a multi-band monopole antenna including one or more aspects of the present disclosure; and

[0022] FIG. 13 is a schematic illustration of another example embodiment of a multi-band monopole antenna including one or more aspects of the present disclosure.

[0023] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0024] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0025] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0026] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having," are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0027] When an element or layer is referred to as being "on", "engaged to", "connected to" or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to", "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

[0028] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. [0029] Spatially relative terms, such as "inner," "outer," "beneath", "below", "lower", "above", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0030] With reference now to the drawings, FIGS. 1 to 4 illustrate an example embodiment of an antenna generally at reference number 100 including one or more aspects of the present disclosure. The illustrated antenna 100 may be integrated in, embedded in, installed to, etc. a wireless application device (not shown), including, for example, a personal computer, a cellular phone, personal digital assistant (PDA), etc. within the scope of the present disclosure.

[0031] As shown in FIGS. 1 to 4, the illustrated antenna 100 is a multiband quarter- wave mono-pole antenna. The antenna 100 includes a first monopole element 102 (also referred to as a first resonant element 102) for connection, at 104, to a feed point of the device in which it is installed. The antenna includes a low band parasitic element 106 (also referred to as a second resonant element 106) for connection, at 108, to a ground, (such as ground plane 110). The antenna also includes a high band parasitic element 112 (also referred to as a third resonant element 112) for connection, at 114 to a ground. As can be seen, the second resonant element 106 is adjacent part of the first resonant element 102. The second resonant element 106 is configured for electromagnetic coupling with the first resonant element 102 when the antenna 100 is operating. The third resonant element 112 is also adjacent part of the first resonant element 102. The third resonant element 112 is configured for electromagnetic coupling with the first resonant element 102 when the antenna 100 is operating.

[0032] The first resonant element 102 is configured to be resonant at more than one frequency. As will be understood by those skilled in the art, although designed to be resonant at certain frequencies, monopole element 102 will resonate across one or more ranges of frequencies, each range encompassing at least one frequency (also referred to as a center frequency) for which the monopole element is designed to be resonant. Each of such frequency ranges has a bandwidth generally ranging from a lowest to a highest frequency in the frequency range. According to some aspects, the first resonant element 102 is configured to resonate in a first frequency range and a second frequency range. The first frequency range and the second frequency range may be different and non-overlapping frequency ranges. The first frequency range and the second frequency range may be referred to as the low-band and the high-band, respectively. According to some embodiments, the first frequency range (or low-band) has a center frequency of about 900 megahertz (MHz) and the second frequency range (or high-band) has a center frequency of about 1800 MHz. According to some embodiments, the first frequency range has a bandwidth from about 809 MHz to about 1039 MHz and the second frequency range has a bandwidth from about 1656 MHz to about 2253 MHz. The first resonant element 102 may be configured to resonate in other frequency ranges without departing from the scope of this disclosure.

[0033] To help minimize or at least reduce the overall size of the antenna 100, monopole element 102 is folded in three dimensions as illustrated in FIGS. 1 to 3. Antennas according to the present disclosure are not limited, however, to antennas with folded elements.

[0034] The low-band parasitic element 106 and the high-band parasitic element 112 are parasitically driven radiators. The parasitic elements 106, 112 are galvanic connected to the ground plane 110 and are driven by non-galvanic electromagnetic coupling to the monopole element 102. Generally, the parasitic elements 106, 112 are coupled with the monopole element 102 in regions where the parasitic elements are substantially parallel to the monopole element 102. For example, low-band parasitic element 106 is electromagnetically coupled with monopole element 102 generally in coupling region 118 shown in FIG. 4. Although illustrated in FIG. 4 as vertical parallel elements, the coupling region 118 may include, as will be seen below, monopole elements 102 and parasitic elements 106, 112 that are vertical, horizontal, wavy, meandering, etc. so long as there is sufficient electromagnetic coupling to drive the parasitic elements 106, 112.

[0035] The length of parasitic elements 106, 112 may be selected so that the parasitic elements 106, 112 resonant at a desired frequency. For example, the length of each parasitic element 106, 112 may be about a quarter wavelength (1/4 λ) of the desired resonant frequency for that parasitic element 106, 112. In this embodiment, the high-band parasitic element 112 is a high frequency radiator and the low-band parasitic element 106 is a low frequency radiator. Accordingly, the high-band parasitic element 112 is shorter than the low-band parasitic element 106. As with the monopole element 102, those skilled in the art will recognize that the parasitic elements will resonate across a range of frequencies encompassing a desired resonant frequency (also referred to as a center frequency). To help minimize or at least reduce the overall size of the antenna 100, parasitic elements 106, 112 are folded in three dimensions as illustrated in FIGS. 1 to 3. Antennas according to the present disclosure are not limited, however, to antennas with folded elements.

[0036] The desired resonant frequency of each parasitic element 106, 112, and accordingly the resulting frequency ranges, may be selected to increase the bandwidth of the resonant frequency ranges of the antenna 100 as compared to an antenna comprising only the monopole element 102. For example, the monopole element 102 may be resonant in a first and a second frequency range, which may be a low-band and a high-band, respectively. The low-band parasitic element 106 may be configured to resonate at a frequency either within or outside of, but generally near, the first frequency range. Whether within or outside of the first frequency range, the low-band parasitic element 106 may have a resonant frequency near the high end or the low end of the first frequency range. When the resonant frequency of the low-band parasitic element is outside, but near, the first frequency range, a portion of the frequency range of the low-band parasitic element 106 (also referred to as a third frequency range) may overlap a portion of the first frequency range. When the resonant frequency of the low-band parasitic element is within the first frequency range, at least a portion of the third frequency range overlaps a portion of the first frequency range, and a portion of the third frequency range may extend beyond the first frequency range. Accordingly, in such various configurations, the low-band parasitic element 106 extends the bandwidth of the first frequency range. The high-band parasitic element 112 extends the bandwidth of the second frequency range in a similar manner. The extension of bandwidth, in any case, does not necessarily mean or require the parasitic element resonate at frequencies for which the monopole element 102 is not otherwise resonant. The monopole may resonate at a certain frequency near the end of a frequency range, but performance at that frequency may not be acceptable, may not be sufficient for the desired use of the antenna 100, etc. Thus, extending the bandwidth of a frequency range can include extending and/or improving, the usable, acceptable, sufficient, etc. bandwidth. [0037] The monopole element 102 may be connected to a feed point of a device in which the antenna 100 is installed. The feed point is the point at which signals from the device are transmitted to the antenna 100 and the point at which signals received by the antenna 100 are passed to the device. The monopole element may be connected to the feed point by any suitable means, such as by soldering, welding, crimping, using connectors, etc.

[0038] In some embodiments, the antenna 100 includes, and/or is supported by, a substrate, such as carrier 116. The substrate may be any suitable nonconductive material. The substrate may be a rigid insulator substrate, such as a circuit board substrate (e.g., Flame Retardant 4 or FR4, etc.), a plastic, (e.g., polycarbonate, acrylonitrile butadiene styrene (ABS)), etc. Alternatively, the substrate may be a flexible insulator, such as a flexible circuit board, flex-film, etc. The antenna 100 may be, or may be part of, a printed circuit board (whether rigid or flexible), where the monopole element 102 and parasitic elements 106, 112 are all conductive traces on the circuit board substrate. The antenna 100 can be a single sided PCB antenna. Alternatively, the antenna 100 (whether mounted on a substrate or not) may be constructed from sheet metal by cutting, stamping, etching, etc.

[0039] An impedance matching component may be coupled between the monopole element 102 and a ground. In FIG. 4 the impedance matching component is illustrated as an inductor connected between the monopole element 102 and ground. In some embodiments, the inductor has an inductance of between 1 nH and 10 nH. In other embodiments, the matching component may be an inductor with an inductance less than 1 nH or greater than 1OnH. The impedance matching component may be an inductor, a capacitor, a combination of inductors and capacitors, a conductive trace on a circuit board, a small wire, etc. In some instances, an impedance matching component may not be needed.

[0040] FIGS. 5 through 8 illustrate analysis results for the antenna 100 in FIGS. 1 through 4. FIG. 5 illustrates a graph of the Sn return loss over a frequency bandwidth of 500 megahertz to 3 gigahertz. FIG. 6 illustrates the voltage standing wave ratio (VSWR) of the antenna 100 over a frequency bandwidth of 500 megahertz to 3 gigahertz. Fig. 7 illustrates the S-parameter Smith chart for the antenna 100 over a frequency bandwidth of 500 megahertz to 1.5 gigahertz. Fig. 8 illustrates the S-parameter Smith chart for the antenna 100 over a frequency bandwidth of 1.5 gigahertz to 3.0 gigahertz. [0041] FIGS. 9 through 13 illustrate several other exemplary embodiments of antennas 200, 300, 400, 500, 600 including one or more aspects of the present disclosure. All of the antennas 200, 300, 400, 500, 600 are generally similar to the antenna 100 discussed above.

[0042] Each of the illustrated antennas 200, 300, 400, 500, 600 includes a monopole element 202, 302, 402, 502, 602, a low-band parasitic element 206, 306, 406, 506, 606 and a high-band parasitic element 212, 312, 412, 512, 612. The parasitic elements 206, 306, 406, 506, 606, 212, 312, 412, 512, 612 are positioned adjacent, and electromagnetically coupled with, at least a portion of the monopole elements 202, 302, 402, 502, 602 in coupling regions 218, 318, 418, 518, 618. The parasitic elements 206, 306, 406, 506, 606, 212, 312, 412, 512, 612 are connected to ground, while the monopole elements 202, 302, 402, 502, 602 are connected to a feed point. Several monopole elements, such as monopole element 202, 402 and 602, include an additional resonant branch 203, 403, 603. Antennas 500 and 600 each includes a monopole element 502, 602 and low band parasitic element 506, 606 having wavy, or meander, portions in coupling region 518.

[0043] As is evident by the various configurations of the illustrated antennas 200, 300, 400, 500, 600, antennas according to the present disclosure may be varied without departing from the scope of this disclosure and the specific configurations disclosed herein are exemplary embodiments only and are not intended to limit this disclosure. For example, as shown by a comparison of FIGS. 1 through 4 with FIGS. 9 through 13, the shape, length, width, orientation, etc. of monopole elements, radiating elements, etc. and/or the inclusion, etc. of branches on the monopole elements may be varied. Additionally, or alternatively, the size, shape, length, width, orientation, etc. of the parasitic elements and their distance from the monopole elements may be varied. As will be understood by one of ordinary skill, one or more of such changes may be made to adapt an antenna to different frequency ranges, to the different dielectric constants of any substrate (or the lack of any substrate), to increase the bandwidth of one or more frequency ranges, enhance one or more other features, etc.

[0044] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims

1. A multi-band antenna comprising: a first resonant element for connection to a feed point; a second resonant element for connection to a ground, the second resonant element adjacent at least part of the first resonant element, the second resonant element configured for electromagnetic coupling with the first resonant element; and a third resonant element for connection to the ground, the third resonant element adjacent at least part of the first resonant element, the third resonant element configured for electromagnetic coupling with the first resonant element.

2. The antenna of claim 1 wherein the first resonant element is resonant in at least a first frequency range and a second frequency range.

3. The antenna of claim 2 wherein the second resonant element is configured to resonate in a third frequency range in response to the first resonant element resonating in the first frequency range.

4. The antenna of claim 3 wherein the third frequency range overlaps the first frequency range.

5. The antenna of claim 4 wherein the third resonant element is configured to resonate in a fourth frequency range in response to the first resonant element resonating in the second frequency range.

6. The antenna of claim 5 wherein the fourth frequency range overlaps the second frequency range.

7. The antenna of claim 3 wherein the third resonant element is configured to resonate in a fourth frequency range in response to the first resonant element resonating in the second frequency range.

8. The antenna of claim 7 wherein the fourth frequency range overlaps the second frequency range.

9. The antenna of claim 1 wherein the second resonant element and the third resonant element are configured to resonate in response to a signal on the first resonant element.

10. The antenna of any of claims 1 through 9 further comprising a non-conductive antenna carrier, the first resonant element, the second resonant element and the third resonant element supported by the antenna carrier.

11. The antenna of any of claims 2 through 8 wherein the second resonant element is configured to increase the bandwidth of the first frequency range.

12. The antenna of any of claims 2 through 8 wherein the third resonant element is configured to increase the bandwidth of the second frequency range.

13. The antenna of any of claims 2 through 8 wherein the first frequency range has a center frequency of about 900 MHz.

14. The antenna of claim 13 wherein the second frequency range has a center frequency of about 1800 MHz.

15. The antenna of any of claims 2 through 8 wherein the second frequency range has a center frequency of about 1800 MHz.

16. A wireless application device including the antenna of any of claims 1 through 9.

17. A multi-band monopole antenna comprising: a monopole element for connection to a feed point, the monopole element configured to resonate in at least a first frequency range and a second frequency range; a low band parasitic element for connection to a ground, the low band parasitic element adjacent at least part of the monopole element, the low band parasitic element configured to resonate to increase a bandwidth of the first frequency range; and a high band parasitic element for connection to the ground, the high band parasitic element adjacent at least part of the monopole element, the high band parasitic element configured to resonate to increase a bandwidth of the second frequency range.

18. The antenna of claim 17 wherein the low band parasitic element and the high band parasitic element are configured to electromagnetically couple with the monopole element.

19. The antenna of claim 18 wherein the low band parasitic element and the high band parasitic element are parasitically driven resonant elements.

20. The antenna of claim 18 wherein the low band parasitic element is configured to resonate in a third frequency range and the high band parasitic element is configured to resonate in a fourth frequency range.

21. The antenna of claim 20 wherein the third frequency range overlaps at least a portion of the first frequency range.

22. The antenna of claim 21 wherein the fourth frequency range overlaps at least a portion of the second frequency range.

23. The antenna of 18 further comprising a non-conductive antenna carrier, the monopole element, the low band parasitic element and the high band parasitic element supported by the antenna carrier.

24. The antenna of any of claims 17 through 23 wherein the first frequency range has a center frequency of about 900 MHz.

25. The antenna of any of claims 17 through 23 wherein the second frequency range has a center frequency of about 1800 MHz.

26. The antenna of claim 24 wherein the second frequency range has a center frequency of about 1800 MHz.

27. A wireless application device including the antenna of any of claims 17 through 23.

28. A wireless application device comprising: a ground plane; a feed for transmitting and receiving radio frequency signals; a multi-band monopole antenna coupled to the ground plane and the feed, the antenna including a monopole element coupled to the feed, a low band parasitic element coupled to the ground plane, and a high band parasitic element coupled to the ground plane; wherein the monopole element is configured to resonate in at least a first frequency range and a second frequency range, the low band parasitic element is adjacent at least part of the monopole element and configured to resonate to increase a bandwidth of the first frequency range, the high band parasitic element is adjacent at least part of the monopole element and configured to resonate to increase a bandwidth of the second frequency range.

29. The wireless application device of claim 28 wherein the low band parasitic element and the high band parasitic element are electromagnetically coupled with the monopole element.

30. The wireless application device of claim 28 wherein the low band parasitic element and the high band parasitic element are parasitically driven resonant elements.

31. The wireless application device of claim 28 wherein the low band parasitic element is configured to resonate in a third frequency range and the high band parasitic element is configured to resonate in a fourth frequency range.

32. The wireless application device of claim 31 wherein the third frequency range overlaps at least a portion of the first frequency range.

33. The wireless application device of claim 32 wherein the fourth frequency range overlaps at least a portion of the second frequency range.

34. The wireless application device of claim 28 further comprising a non-conductive antenna carrier, and the monopole element, the low band parasitic element and the high band parasitic element supported by the antenna carrier.

35. The wireless application device of any of claims 28 through 34 wherein the first frequency range has a center frequency of about 900 MHz.

36. The wireless application device of any of claims 28 through 34 wherein the second frequency range has a center frequency of about 1800 MHz.

37. The wireless application device of claim 35 wherein the second frequency range has a center frequency of about 1800 MHz.

38. The wireless application device of any of claims 28 through 34 wherein the high band parasitic element is a parasitically driven one-quarter wavelength radiator.

39. The wireless application device of any of claims 28 through 34 wherein the low band parasitic element is a parasitically driven one-quarter wavelength radiator.

40. The wireless application device of claim 38 wherein the low band parasitic element is a parasitically driven one-quarter wavelength radiator.

41. The wireless application device of any of claims 28 through 34 wherein the first frequency range has a bandwidth from about 809 MHz to about 1039 MHz.

42. The wireless application device of any of claims 28 through 34 wherein the second frequency range has a bandwidth from about 1656 MHz to about 2253 MHz.