Power amplifier with large output power

Abstract

A power amplifier includes n power units A i TL is used to combine n output transmission lines from the power unit. 1i and an impedance transformation network (ITN) of number n i Where i = 1, ..., n. A number of n output transmission lines are connected in series. The output terminal of each power unit is connected to its output transmission line via its impedance transformation network. Each impedance transformation network is an upward impedance transformation network used to transform the output impedance of each power unit at the input terminal of the impedance transformation network to a higher impedance at the output terminal of the impedance transformation network. The power amplifier further includes a number of n input transmission lines TL connected in series. 0i (i=1, 2…n), and the input terminal of the i-th power unit is connected to the second terminal of the i-th transmission line via a capacitor, where i=1,…n. The entire input port of the PA is connected to the first transmission line (TL). 01 Connect to the first terminal of ).

Description

Technical Field

[0001] The embodiments described herein relate to power amplifiers. In particular, they relate to power amplifiers with high output power, transmitters including power amplifiers, and electronic devices. Background Technology

[0002] Power amplifiers (PAs) are widely used in applications such as wireless base stations and user equipment in wireless communication systems, as well as in radar systems. Power amplifiers in transmitters typically amplify the input signal into an output signal ready for radio transmission. In microwave or millimeter-wave transmitters, PAs need to deliver high output power for long-range communication or radar detection. One way to increase output power is to combine the output power from several power units (i.e., transistors) on a chip. The power combiner must constructively (i.e., in-phase) add the output power from the power units and provide impedance matching for each power unit and the external load impedance.

[0003] like Figure 1 As shown, it consists of two quarter wavelengths (λ) g / 4) A 2-way Wilkinson power combiner consisting of a transmission line and a resistor is widely used. A 4-way power combiner can be composed of three Wilkinson power combiners. To minimize the combiner's footprint and losses, short microstrip transmission lines (e.g., λ) can be used. g / 36), and omitting resistors in Wilkinson power combiners, such as those presented by E. Ojefors et al. at the 2014 Proceedings of the 9th European Microwave Integrated Circuits Conference. An 8- Way Power-Combining E-band Amplifier in a SiGe HBT technology The 8-way power combiner disclosed in (pages 45-48) presents a high impedance (e.g., >50Ω) for each power unit.

[0004] like Figure 2 As shown, transformers are often used for combined power. Transformers can be configured as follows: Figure 2 Series combination of power as shown in (a) or as Figure 2 Parallel power combinations are shown in (b). Figure 2 Mixed series and parallel combinations, as shown in (c), are also possible.

[0005] For series-combined transformers, the power combiner provides approximately R to each power unit. load The impedance of / N, where R loadThis is the impedance of the output port, and N is the number of power units. For a parallel combined transformer, the impedance of each power unit is N*R. load .

[0006] It should be noted that, for the sake of high output power, series-connected transformers are superior to parallel-connected transformers because lower impedance is desired for the power units or transistors. Assuming R... opt R is the inherent load required for the transistor to deliver its peak output power, and is given by the following formula: opt

[0007]

[0008] Where V dd It is the drain voltage bias, V k This is the transistor's knee voltage. P peak This represents the peak output power. Equation (1) shows that: P peak The larger R is opt The smaller.

[0009] Output power can also be combined by using transmission lines in series. For example... Figure 3 The amplifier shown is a so-called distributed amplifier (DP), where the drain parasitic capacitance Cd and the transmission line Ld form an artificial transmission line. Input power is distributed to each transistor via another artificial transmission line at the gate (i.e., the Lg and Cg sections). If the gate and drain transmission lines provide the same phase shift, the drain current from multiple transistors at the load Z... od The components are constructively added together. In terms of losses, the combination via transmission lines is superior to the combination via transformers because it avoids the losses associated with the secondary windings and the coupling between the two windings.

[0010] The distributed amplifier mentioned above has a gain response spanning the frequency range from DC to the cutoff frequency; it is a low-pass amplifier. At the 2005 European Microwave Conference (EuMC), NP Mehta and PNSHastry presented their findings. Design guidelines for a novel bandpass distributed amplifier (Pages 1-4) and H. Rashtian and O. Momeni's article in IEEE Transactions on Microwave Theory and Technology, Volume 67, 2019. Gain boosting in distributed amplifiers for close- TO-FMAX operation in silicon The text introduces the concept of "in". Figure 4 The bandpass distributed amplifier shown has shunt inductors L2 added at both the gate and drain transmission lines. Capacitor Cb is used for DC decoupling.

[0011] However, uniformly distributed amplifiers in which the transmission lines have the same width and length have the following disadvantages, such as: the input power of each transistor is not equal because the preceding transistors take away a portion of the power; a portion of the output power propagates to the left and is dissipated at resistor Zod; and the transistors are not loaded equally or optimally because the load of the transistors is modulated by the output current from other transistors.

[0012] Therefore, as Figure 5 As shown, a non-uniformly distributed power amplifier is suggested to address those problems. This non-uniformly distributed power amplifier is discussed in CFCampbell's article, "...", published in IEEE Microwave Magazine, Volume 20, No. 1, 2019. Evolution of the nonuniform distributed power amplifier (Disclosed on pages 18-27). In the non-uniform DP, the resistor Zod is removed and the drain of the leftmost transistor is connected to a terminal of the transmission line at the drain. Each transmission line has a different width and therefore a different characteristic impedance. ( i =1, 2…N). The characteristic impedance of the transmission line at the drain decreases from left to right to force most of the drain current to flow to the load. Additionally, a capacitor is added at the gate of the transistor. ( i =1, 2...N). The capacitance is decreased from left to right to balance the input power of each transistor. Capacitor It can also increase the cutoff frequency.

[0013] Recently, in the November 2018 issue of IEEE Transactions on Microwave Theory and Technology, Volume 66, No. 11, P. Saad et al. published an article titled "..." A 1.8-3.8-GHz power amplifier with 40% efficiency at 8-dB power back-off (Pages 4870-4882) suggested the following: Figure 6 The design shown is a distributed high-efficiency power amplifier (DEPA) with an ultra-wide bandwidth DPA.

[0014] Existing power combination solutions have some problems, such as:

[0015] Wilkinson power combiners, especially those using quarter-wavelength transmission lines and multi-channel power combiners, have a relatively large footprint. Minimized microstrip power combiners have impedances >50Ω at the power cell ports, thus requiring additional impedance matching networks, such as transformers, to transform this high impedance into transistor impedances. opt ;

[0016] The limited quality factor makes transformer-based combiners quite lossy at millimeter waves, with transformer losses exceeding 1.2 dB.

[0017] for Figure 6 The optimal admittance required by the DEPA in the auxiliary amplifier. It should be equal to the admittance difference between adjacent transmission line sections. If R opt If it is too small, the required admittance difference will be difficult to achieve in actual implementation. Summary of the Invention

[0018] Therefore, the purpose of the embodiments described herein is to provide a power amplifier with improved power combination.

[0019] According to one aspect, the objective is achieved through a power amplifier. The power amplifier includes n power units A. i , where i=1, ...,n, and each power unit has an input terminal and an output terminal.

[0020] The power amplifier further includes n output transmission lines TL for combining the output power from the power unit. 1i , where i=1, ...,n. Each output transmission line has a first terminal and a second terminal, and the second terminal of the i-th transmission line is connected to the first terminal of the (i+1)-th transmission line, so that n output transmission lines are connected in series.

[0021] The power amplifier further includes n impedance transformation networks (ITNs). i ), where i=1, ...,n, and each impedance transformation network has input terminals and output terminals.

[0022] The output terminal of the i-th power unit is connected to the input terminal of the i-th impedance transformation network, and the output terminal of the i-th impedance transformation network is connected to the first terminal of the i-th output transmission line.

[0023] Each impedance transformation network is an upward impedance transformation network used to transform the output impedance of each power unit at the input terminal of the impedance transformation network into a higher impedance at the output terminal of the impedance transformation network.

[0024] The power amplifier proposed according to the embodiments herein combines the output power of multiple power units of transistors, such as those in a common-source configuration, via a series-connected transmission line. The drain of the transistor is connected to the transmission line via an impedance transformation network, which can be a tapped capacitor or a tapped inductor impedance transformation network. This tapped capacitor or inductor impedance transformation network up-converts the impedance and releases the load from the transistor to the transmission line. Therefore, it provides a power amplifier with a small R...opt Large transistors provide impedance matching and enable transistors to deliver large output power.

[0025] The power amplifiers proposed according to the embodiments herein have several advantages:

[0026] The output power of transistors is combined by series connection through transmission lines, which provides relatively low impedance for each power unit compared to parallel connection of transformers or Wilkinson power combiners.

[0027] The transmission lines in the proposed power amplifier can be non-uniform, and the power combination using non-uniform transmission lines has lower losses and a smaller footprint compared to series-combined transformers.

[0028] By adding an upward impedance transformation network at the non-uniform distributed amplifier, the small R of the large transistor is matched. opt It is possible to obtain high output power.

[0029] Tapped capacitor or inductor impedance transformation networks can utilize only two passive components and therefore have a small footprint.

[0030] The parasitic capacitance of a transistor can be part of a tapped capacitor impedance transformation network.

[0031] Therefore, the power amplifier according to the embodiments herein provides an improved power combiner and can achieve high output power. Attached Figure Description

[0032] The various aspects of the embodiments disclosed herein, including their specific features and advantages, will be readily understood from the following detailed description and accompanying drawings, wherein:

[0033] Figure 1 This is a schematic block diagram illustrating a 2-way Wilkinson power combiner;

[0034] Figure 2 (a)-(c) are schematic block diagrams illustrating the power combination through the transformer;

[0035] Figure 3 This is a schematic block diagram illustrating the equivalent circuit of a distributed amplifier based on lumped element artificial transmission lines;

[0036] Figure 4 This is a schematic block diagram illustrating a bandpass distributed amplifier;

[0037] Figure 5 This is a schematic block diagram illustrating a non-uniformly distributed power amplifier;

[0038] Figure 6This is a schematic block diagram illustrating the architecture of a distributed high-efficiency power amplifier (DEPA).

[0039] Figure 7 This is a schematic block diagram illustrating a power amplifier according to embodiments described herein;

[0040] Figure 8 (a) and (b) are schematic block diagrams illustrating examples of impedance transformation networks (ITNs) according to embodiments herein;

[0041] Figure 9 (a)-(d) are the equivalent circuits of a transistor with a tapped capacitor impedance transformation network;

[0042] Figure 10 This is a schematic block diagram illustrating an example power amplifier according to the embodiments described herein;

[0043] Figure 11 This is a graph illustrating the gain of the PA according to the embodiments described herein;

[0044] Figure 12 This is a graph illustrating the efficiency of the PA according to embodiments herein; and

[0045] Figure 13 This is a block diagram illustrating an electronic device in which a power amplifier according to embodiments herein can be implemented. Detailed Implementation

[0046] Where applicable, similar reference numerals have been used throughout the following description to denote similar features such as elements, units, modules, circuits, nodes, parts, items, etc.

[0047] Figure 7 A schematic diagram of a proposed power amplifier 700 with an upward impedance transformation network according to an embodiment herein is shown.

[0048] The power amplifier 700 includes n power units Ai, where i = 1, ..., n. Each power unit has an input terminal Ain and an output terminal Aout.

[0049] The power amplifier 700 further includes n output transmission lines TL for combining the output power from the power unit. 1i Where i = 1, ..., n. Each output transmission line has a first terminal T1 and a second terminal T2. The i-th transmission line TL 1i The second terminal is connected to the (i+1)th transmission line TL 1(i+1) The first terminal allows n output transmission lines to be connected in series. For example, the first transmission line TL 11The second terminal T2 is connected to the second transmission line TL 12 The first terminal T1.

[0050] The power amplifier 700 further includes n impedance transformation networks (ITNs). i Where i = 1, ..., n. Each impedance transformation network has an input terminal ITNin and an output terminal INTout. The output terminal Aout of the i-th power unit is connected to the input terminal ITNin of the i-th impedance transformation network, and the output terminal ITNout of the i-th impedance transformation network is connected to the first terminal T1 of the i-th output transmission line. For example, the output terminal of the second power unit A2 is connected to the input terminal of the second impedance transformation network, and the output terminal of the second impedance transformation network is connected to the second output transmission line TL. 12 The first terminal.

[0051] Each impedance transformation network is an upward impedance transformation network used to transform the output impedance of each power unit at the input terminal of the impedance transformation network into a higher impedance at the output terminal of the impedance transformation network.

[0052] Each output transmission line in the output transmission line can have the same width and length or can have different widths and lengths.

[0053] The power amplifier may further include n input transmission lines TL connected in series. 0i Each input transmission line has a first terminal and a second terminal, wherein the second terminal of the i-th input transmission line is connected to the first terminal of the (i+1)-th input transmission line, and wherein the input terminal of the i-th power unit is connected to the second terminal of the i-th transmission line via a capacitor, where i=1,…n. Connect the entire PA's input port Pin to the first transmission line TL. 01 Connect to the first terminal.

[0054] like Figure 8 As shown in (a) and (b), each impedance transformation network INT can be a tapped capacitor impedance transformation network or a tapped inductor impedance transformation network. Figure 8 As shown in (a), the tapped capacitor impedance transformation network may include a first capacitor C1 and a second capacitor C2 connected in series, wherein the second terminal of the first capacitor is connected to the first terminal of the second capacitor to form a tapped node. The input terminal INTin of the impedance transformation network is connected to the tapped node, the output terminal INTout of the impedance transformation network is connected to the first terminal of the first capacitor C1, and the second terminal of the second capacitor C2 is grounded.

[0055] like Figure 8As shown in (b), the tapped inductor impedance transformation network may include a first inductor L1 and a second inductor L2 connected in series. The second terminal of the first inductor L1 is connected to the first terminal of the second inductor L2 to form a tapped node. The input terminal INTin of the impedance transformation network is connected to the tapped node, the output terminal INTout of the impedance transformation network is connected to the first terminal of the first inductor L1, and the second terminal of the second inductor L2 is grounded.

[0056] Below, the principle and performance of the recommended power amplifier 700 will be analyzed.

[0057] Each power unit can be a common-source transistor. It should be connected to two transmission lines TL. 1i Each transistor connected to the connection point is matched to ,in It has an input impedance of R opt The output impedance of ITN. The reciprocal of, that is It needs to be matched to the admittance difference:

[0058]

[0059] Z i The impedance Z is the impedance viewed to the left from the junction of the two transmission lines. i+1 This is the impedance viewed to the right from the junction of the two transmission lines, as shown in... Figure 7 As shown by Z1 and Z2 in the diagram. Impedance Z i It depends on the length and width of the TL and the load of the adjacent transistor on the left or right. The larger the impedance, the easier impedance matching. Unfortunately, to deliver high output power, large transistors have small impedance ratios. opt Furthermore, large transistors have large parasitic capacitances on the transmission lines at the drain. These parasitic capacitors, together with the transmission lines, form artificial transmission lines.

[0060] The upward impedance transformation network will reduce the small R opt And large parasitic capacitance converted into large And small capacitance, i.e. high impedance. The parasitic capacitance of a transistor can be part of an upward impedance transformation network.

[0061] Figure 9 The diagram shows a tapped capacitor impedance transformation network connected to a transistor. It consists of a shunt parasitic capacitor C. d Norton's equivalent circuit (i.e., current source I) d ) represents a transistor. And as... Figure 9 As shown in (a), R optThis is the impedance that should be provided by the tapped capacitor impedance transformation network. C1 and C2 represent two capacitors in the tapped capacitor impedance transformation network.

[0062] Figure 9 (b) shows the merger of C2 and C d The subsequent equivalent circuit, in which , Parasitic capacitance C d It becomes part of a tapped capacitor impedance transformation network. And R2 equals R opt .

[0063] Figure 9 (c) shows the resistor R2 and capacitor (C2+C) connected in parallel. d The equivalent circuit after being converted into a series circuit.

[0064] Figure 9 (d) shows the equivalent circuit after converting the series-connected capacitors and resistors into parallel connections.

[0065] In order to obtain such Figure 9 The equivalent R of the parallel connection of the tapped capacitor matching network shown in (d) t and C t , use as Figure 9 The series connection shown in (c) and Replacement Figure 9 The capacitors connected in parallel as shown in (b) and resistor R2, and

[0066]

[0067] Where Q2 is R2 and R2 connected in parallel. Q factor:

[0068] .

[0069] Equivalent capacitance C eq C1 and representing series connection The total capacitance is given by the following formula.

[0070]

[0071] if ,but .

[0072] In addition, series connection and C eq The Q factor is defined as

[0073]

[0074] if ,but .

[0075] Finally, the equivalent R for parallel connection is given by the following equation. t and C t

[0076]

[0077] if and ,but

[0078]

[0079] From equations (3)-(7), it can be found that using a tapped capacitor matching network increases the resistance by approximately [percentage missing]. The capacitance is reduced by a factor of [number], and the capacitance is reduced to approximately [percentage] of the capacitance. Note that R t Representative (2) .

[0080] It should be noted that the tapped capacitor impedance transformation network is only an example embodiment. Other types of upward impedance matching networks can also be used. For example, two capacitors can be replaced with two inductors to form a tapped inductor impedance transformation network. Furthermore, π or T networks can also be used. However, π or T networks consist of at least three passive components and have a larger footprint than tapped capacitor and inductor impedance transformation networks.

[0081] Therefore, according to some embodiments, each upward impedance transformation network may include a T-impedance matching network, which includes at least three passive components connected in a T-shape.

[0082] According to some embodiments, each impedance transformation network may include a π-impedance matching network, which includes at least three passive components connected in a π-shape.

[0083] According to some embodiments, each impedance transformation network may include a transformer.

[0084] According to some embodiments, each power unit may include a common-source configured transistor, with the gate of each transistor connected to the input terminal of the power unit and the drain of each transistor connected to the output terminal of the power unit, and the source of each transistor grounded.

[0085] Figure 10An example embodiment of a 70-88GHz PA 1000 targeting high output power is shown. This PA has four transistors in a common-source configuration. Each drain of the transistor is connected to a source transistor via a capacitor. di and C dii Connect the tapped capacitor matching network consisting of (i=1, 2, 3, 4). Connect each tapped capacitor impedance transformation network to the network except for the one connected to TL. 11 The first output transmission line TL is connected to the first terminal. 1i The connection points (i=1, 2, 3, 4) are connected. The width of TLs increases from left to right. Therefore, the characteristic impedance of TLs decreases accordingly. Drain bias is provided through an AC choke. In addition to connecting the final capacitor C... g4 with TL 04 In addition to being connected to the second terminal, each gate of the transistor is connected via capacitor C. gi (i=1, 2, 3, 4) and input transmission line TL 0i Connect the points (i=1, 2, 3, 4) together. C gi The capacitance increases from left to right to keep the input signals of all transistors at the same amplitude. Gate resistor R g It is inserted between the transistor's gate and gate bias to prevent RF signal leakage. The input port is connected to the first transmission line TL. 01 Connect to the first terminal.

[0086] Figure 11 The gain versus output power curves for the PA at frequencies of 70 GHz, 76 GHz, 82 GHz, and 88 GHz are shown. The small-signal gain of the PA 1000 varies between 4.2 dB and 6.6 dB at different frequencies. For those frequencies, the gain decreases by no more than 2.5 dB as the output power increases. The maximum output power of the PA varies between 33.8 dBm and 34.7 dBm for different frequencies.

[0087] Figure 12 The power-added efficiency (PAE) of the PA 1000 is shown at frequencies of 70 GHz, 76 GHz, 82 GHz, and 88 GHz. The maximum PAE varies between 16% and 24% at different frequencies.

[0088] In summary, PA 700, 1000 according to the embodiments herein are connected in series via transmission line TL 1i (i=1, 2…n) to combine multiple power units or transistors A iThe output power (i=1, 2…n). These transmission lines can have different widths and lengths. The drain of the transistor is connected to the transmission line via an impedance transformation network. This impedance transformation network can be a tapped capacitor or inductor network that up-converts the impedance, that is, converts the low impedance at the input terminal of the impedance transformation network connected to the drain to the high impedance at the output terminal of the impedance transformation network. The output terminal of the impedance transformation network is connected to the transmission line, and the output terminal of the impedance transformation network disconnects the load from the transistor to the transmission line TL. 1i Therefore, it is suitable for applications with small R. opt The large transistors provide impedance matching to increase output power.

[0089] Transmission lines TL connected in series 0i (i=1, 2…n) and the capacitor C at the gate gi The input power is distributed using capacitors (i=1, 2…n). These capacitors can have different capacitances and can help balance the input power of each transistor.

[0090] Power amplifiers 700 and 1000 according to embodiments herein can be used in various electronic devices. Figure 13 A block diagram of electronic device 1300 is shown. Electronic device 1300 may be, for example, a radio frequency transceiver, transmitter, wireless communication device, user equipment, mobile device, base station, or wireless network node in a wireless communication system, or any general-purpose electronic circuit or device requiring a power amplifier. Electronic device 1300 may include other units, of which processing unit 1310 and memory 1320 are shown.

[0091] When the word “includes” or “contains” is used, it should be interpreted as non-restrictive, meaning “consisting of at least…”.

[0092] The embodiments described herein are not limited to those described above. Various alternatives, modifications, and equivalents may be used. Therefore, the above embodiments should not be considered as limiting the scope of the invention, which is defined by the appended claims.

Claims

1. A power amplifier (700, 1000), comprising: Power unit A with a quantity of n i Where i = 1, ..., n, each power unit has an input terminal (Ain) and an output terminal (Aout); The number of output transmission lines TL is n 1i Where i = 1, ..., n, the number of n output transmission lines TL 1i For combining the output power from the power unit, each output transmission line has a first terminal (T1) and a second terminal (T2), the second terminal (T2) of the i-th transmission line is connected to the first terminal (T1) of the (i+1)-th transmission line, such that the n output transmission lines are connected in series. as well as An impedance transformation network (ITN) with n nodes i Where i = 1, ..., n, each impedance transformation network has an input terminal (ITNin) and an output terminal (ITNout); Specifically, the output terminal of the i-th power unit is connected to the input terminal of the i-th impedance transformation network, and the output terminal of the i-th impedance transformation network is connected to the first terminal of the i-th output transmission line. Each impedance transformation network is an upward impedance transformation network, which is used to transform the output impedance of each power unit at the input terminal of the impedance transformation network into a higher impedance at the output terminal of the impedance transformation network.

2. The power amplifier (700, 1000) according to claim 1, wherein, Each power unit includes a common-source transistor, wherein the gate of each transistor is connected to the input terminal of the power unit, and the drain of each transistor is connected to the output terminal of the power unit, and the source of each transistor is grounded.

3. The power amplifier (700, 1000) according to claim 1, wherein, Each impedance transformation network is a tapped capacitor impedance transformation network comprising a first capacitor and a second capacitor connected in series, wherein the second terminal of the first capacitor is connected to the first terminal of the second capacitor to form a tapped node, and wherein the input terminal of the impedance transformation network is connected to the tapped node, the output terminal of the impedance transformation network is connected to the first terminal of the first capacitor, and the second terminal of the second capacitor is grounded.

4. The power amplifier (700, 1000) according to claim 3, wherein, The parasitic capacitance of the transistor in each power unit is part of the tapped capacitor impedance transformation network.

5. The power amplifier according to claim 1, wherein, Each impedance transformation network is a tapped inductor impedance transformation network comprising a first inductor and a second inductor connected in series, wherein the second terminal of the first inductor is connected to the first terminal of the second inductor to form a tapped node, and wherein the input terminal of the impedance transformation network is connected to the tapped node, the output terminal of the impedance transformation network is connected to the first terminal of the first inductor, and the second terminal of the second inductor is grounded.

6. The power amplifier according to claim 1, wherein, Each impedance transformation network includes a T-impedance matching network, which comprises at least three passive components connected in a T-shape.

7. The power amplifier according to claim 1, wherein, Each impedance transformation network includes a π-impedance matching network, which comprises at least three passive components connected in a π-shape.

8. The power amplifier according to claim 1, wherein, Each impedance transformation network includes a transformer.

9. The power amplifier according to any one of claims 1 to 8, wherein, The output transmission lines have different widths and lengths.

10. The power amplifier according to any one of claims 1 to 8, wherein, Each of the output transmission lines has the same width and length.

11. The power amplifier according to any one of claims 1 to 8, further comprising n input transmission lines TL connected in series. 0i (i = 1, 2…n), each input transmission line has a first terminal and a second terminal, wherein the second terminal of the i-th transmission line is connected to the first terminal of the (i+1)-th transmission line, and wherein, The input terminal of the i-th power unit is connected to the second terminal of the i-th transmission line via a capacitor, where i = 1, ..., n. The entire input port of the PA is connected to the first transmission line (TL). 01 Connect to the first terminal of ).

12. An electronic device comprising a power amplifier according to any one of claims 1 to 11.

13. The electronic device according to claim 12, wherein the electronic device is any one of a transmitter, transceiver, base station, mobile device, or user equipment in a wireless communication system.

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