TECHNICAL FIELD

This disclosure relates generally to communications or signal processing with electronic devices and, more specifically, to implementing an amplifier that is divided by a switch matrix.

BACKGROUND

Electronic devices include traditional computing devices such as desktop computers, notebook computers, smartphones, wearable devices like a smartwatch, internet servers, and so forth. However, electronic devices also include other types of computing devices such as personal voice assistants, robotics, automotive electronics, thermostats and other sensors or automated controllers, devices embedded in other machines like refrigerators and industrial tools, Internet of Things (IoT) devices, and so forth. These various electronic devices provide services relating to productivity, communication, social interaction, security, safety, remote management, entertainment, transportation, and information dissemination. Thus, electronic devices play crucial roles in many aspects of modern society.

Many of the services provided by electronic devices in today's interconnected world depend at least partly on electronic communications. Electronic communications include, for example, those exchanged between or among different electronic devices using wireless or wired signals that are transmitted over one or more networks, such as the Internet, a Wi-Fi network. or a cellular network. Electronic communications therefore include both wireless and wired transmissions and receptions. To make such electronic communications, an electronic device uses a transceiver, such as a wireless transceiver.

Electronic communications can therefore be realized by propagating signals between two wireless transceivers at two different electronic devices. For example, using a wireless transmitter, a smartphone can transmit a wireless signal to a base station over an air medium as part of an uplink communication to support mobile services. Using a wireless receiver, the smartphone can receive a wireless signal from the base station via the air medium as part of a downlink communication to enable mobile services. With a smartphone, mobile services can include phone and video calls, social media interactions, messaging, watching movies, sharing videos, performing searches, acquiring map information or navigational instructions, finding friends, location-based services generally, transferring money, ordering a good or service like a car ride, and so forth.

To provide these and other types of services, electronic devices typically use a wireless transceiver to communicate wireless signals in accordance with some wireless standard. Examples of wireless standards include an IEEE 802.11b or 802.11g Wi-Fi standard and a Fourth Generation (4G) cellular standard, both of which are used today with smartphones and other connected devices. However, efforts to enable faster wireless networks through the creation of newer wireless standards are ongoing. Next-generation cellular networks and new Wi-Fi networks, for example, are expected to offer significantly higher bandwidths, lower latencies, and access to additional electromagnetic spectrum. Taken together, this means that exciting new wireless services can be provided to users, such as self-driving vehicles, augmented reality (AR) and other mixed reality (MR) imaging, on-the-go 4K video streaming, ubiquitous sensors to keep people safe and to use natural resources more efficiently, real-time language translations, and so forth.

To make these new, faster wireless technologies more widely available, many wireless devices besides smart phones will be deployed, which is sometimes called the “Internet of Things” (IoT). Compared to today's use of wireless devices, tens of billions, and eventually trillions, of more devices are expected to be connected to the internet with the arrival of the Internet of Things. These IoT devices may include small, inexpensive, and low-powered devices, like sensors and tracking tags. Further, to enable next-generation wireless technologies, Fifth Generation (5G) cellular wireless devices, Wi-Fi 6 devices, and devices adhering to Licensed Assisted Access (LAA) schemes will each be communicating with signals that use wider frequency ranges that are located at higher frequencies of the electromagnetic (EM) spectrum as compared to those devices that operate in accordance with older wireless standards. For example, newer devices will be expected to provide channel bandwidths over 20 Megahertz (MHz) and to operate at millimeter wave (mmW) frequencies. These “mmW frequencies” can include frequencies between at least 30 and 300 Gigahertz (GHz), but they also include 20 GHz frequency and frequencies as low as 3-6 GHz. A version of LAA that is promulgated by the 3rd Generation Partnership Project (3GPP), for example, operates in a 5 GHz band.

To accommodate these commercial expectations and surmount the associated technical hurdles, the components that enable wireless communications under these constraints will be expected to operate efficiently at higher frequencies. One component that facilitates electronic communication is the wireless interface device, which can include a transceiver and a radio-frequency front-end (RFFE) for communicating with wireless signals. However, the wireless interface devices designed for electronic devices that operate in accordance with the Wi-Fi and 4G cellular standards of today are not adequate for the faster Wi-Fi 6, LAA, and 5G-capable devices of tomorrow because such devices will confront higher frequencies, more-stringent latency demands, and tighter fiscal constraints.

Consequently, to facilitate the adoption of newer and faster wireless technologies, as well as the widespread deployment of wireless interface devices that can provide new capabilities and services, wireless interface devices will be deployed having designs that can handle wider channel bandwidths and higher frequencies, including mmW frequencies. Electrical engineers and other designers of electronic devices are therefore striving to develop new wireless interface devices that will enable the promise of Wi-Fi 6, LAA, 5G and other higher-bandwidth and higher-frequency technologies to become a reality.

SUMMARY

The developing wireless standards for Wi-Fi 6 networks and Licensed Assisted Access (LAA) or 5G wireless communications are intended to establish broadband capabilities at higher frequencies in the gigahertz (GHz) range, including wireless communications providing broader channel bandwidths using frequencies of more than 3 GHz. To facilitate wireless communications at higher bandwidths, some electronic devices employ carrier aggregation. Due to a desire to utilize available frequency spectrum or because of frequency-licensing constraints, some wireless electronic devices employ noncontiguous carrier aggregation (NCCA). NCCA involves combining carriers that are not adjacent to one another on the electromagnetic (EM) frequency spectrum to obtain a wider total bandwidth.

Generally, a broadband component of a device can handle signals having a wider frequency range as compared to a narrowband component. Consequently, fewer broadband components can be used to cover a given frequency range, and using fewer broadband components can result in more compact circuitries to thereby enable smaller electronic devices. Circuitries that include an EM component, such as a transformer, are sometimes realized as narrowband components relative to those that do not include an EM component. If narrowband components and broadband components are both utilized along a component chain for signal processing, there may be a greater quantity of the narrowband components than of the broadband components. This can occur because one broadband component can cover a broadband frequency range corresponding to a combination of multiple narrowband frequency ranges.

In example implementations, a receive chain includes one or more port interfaces and at least one downlink pipe (DLP). Each port interface includes a transformer, which may be a narrowband component. Each DLP includes, for example, a low-noise amplifier (LNA), a mixer, a filter, and so forth. Accordingly, the port interfaces can outnumber the DLPs if the DLPs are realized using broadband components. To couple a selected port interface of multiple port interfaces to an individual DLP of multiple DLPs, a switch matrix is deployed between the multiple port interfaces and the multiple DLPs. Signals propagating across the switch matrix are attenuated to some degree. This signal attenuation is typically frequency dependent. The attenuation can be greater, for instance, for relatively higher frequency signals as compared to relatively lower frequency signals.

To counteract the amplitude attenuation caused by a switch matrix, a signal, such as a higher frequency signal, can be amplified prior to propagation across the switch matrix. In a receive chain context, if a second LNA were to be employed for this prior amplification, the receive chain would include several additional components to accommodate the second LNA. These additional components could include another EM element, an impedance-matching component, an alternating-current (AC) coupling capacitor, and an additional bias circuit. The second LNA would also use additional current. Further, employing two LNAs introduces appreciable nonlinearity that can adversely impact the processing of signals.

In contrast, instead of using two separate LNAs, described implementations utilize a divided amplifier to counteract the attenuation experienced by signals traversing a switch matrix. Example implementations employ an amplifier that can include multiple portions (e.g., stages) that are divided by a switch matrix. In some scenarios, the amplifier can operate like an LNA as part of a receive chain. As part of a receive chain, a first portion of the amplifier is on one side of the switch matrix—e.g., on a communications-processor side of the switch matrix. A second portion of the amplifier is on another side of the switch matrix—e.g., on an antenna side of the switch matrix. A divided amplifier can operate as a multi-stage amplifier in which a main stage is realized as the second portion of the amplifier and a cascode stage is realized as the first portion of the amplifier.

In some implementations, multiple port interfaces are coupled to multiple downlink pipes (DLPs) via a switch matrix. The multiple port interfaces and the multiple DLPs facilitate the processing of signals having different carrier frequencies to support NCCA. A first portion of an amplifier can be included as part of a DLP. The first portion amplifies a signal after the signal propagates over the switch matrix but prior to the signal being applied downstream to a mixer of the DLP. A second portion of the amplifier can be incorporated as part of a first port interface that includes a first transformer and a first switch component. To activate the first port interface to process a received signal, the first switch component is engaged to enable the second portion of the amplifier to amplify the received signal “prior” to forwarding the received signal. This “partially-amplified” signal is then forwarded across the switch matrix to the first portion of the amplifier. The first portion of the amplifier further amplifies the partially-amplified signal before providing the amplified signal to the mixer.

With a cascode amplifier arrangement, for instance, a same current can be used for both the first and second portions of the amplifier. For lower-frequency signals that traverse the switch matrix without appreciable attenuation, the second portion of the amplifier can be omitted from a port interface that corresponds to the lower frequency band. Thus, a second port interface can include a second transformer and a second switch component that selectively permits a signal coupled to the second port interface to be passed to the switch matrix without prior amplification by the amplifier. Two-stage amplification provided by a divided amplifier can therefore be selectively instituted based on a frequency of a received signal.

Thus, employing an amplifier that is divided by a switch matrix across a port interface and a DLP can facilitate use of NCCA while obviating usage of a second LNA. The signal attenuation of higher-frequency signals that occurs as such signals propagate over the switch matrix is compensated for by the divided amplifier. By avoiding use of a second LNA to address the signal attenuation caused by a switch matrix, an additional EM element, an additional impedance-matching component, an additional AC-coupling capacitor, and an additional bias circuit can be avoided. The non-linearity introduced by using two LNAs in series is also avoided. Further, employing certain implementations described herein can save power by reducing current usage. For example, a multi-stage cascode amplifier can use a same current that flows between two power distribution nodes (e.g., between a supply voltage node and a ground node) and also flows through different stages, or portions, of the amplifier.

In an example aspect, an apparatus for processing a signal is disclosed. The apparatus includes a first portion of an amplifier. The apparatus also includes a first port interface. The first port interface includes a first transformer and a second portion of the amplifier, with the second portion of the amplifier coupled to the first transformer. The first port interface also includes a first switch component coupled to at least one of the first transformer or the second portion of the amplifier. The apparatus additionally includes a second port interface. The second port interface includes a second transformer and a second switch component coupled to the second transformer. The apparatus further includes a switch matrix. The switch matrix is coupled between the first switch component and the first portion of the amplifier. The switch matrix is also coupled between the second switch component and the first portion of the amplifier. The switch matrix is further coupled between the second portion of the amplifier and the first portion of the amplifier.

In an example aspect, an apparatus for processing a signal is disclosed. The apparatus includes first amplification means for amplifying a signal. The apparatus also includes a first port interface that includes a first transformer. The first port interface also includes second amplification means for amplifying the signal, with the second amplification means coupled to the first transformer. The first port interface further includes first activation means for activating the first port interface. The apparatus additionally includes a second port interface that includes a second transformer. The second port interface also includes second activation means for activating the second port interface. The apparatus further includes matrix means for providing signal paths that couple the first port interface and the second port interface to the first amplification means.

In an example aspect, a method for processing signals is disclosed. The method entails, for instance, operating a divided amplifier. The method includes accepting a first signal at a first transformer and routing the first signal from the first transformer to a second portion of an amplifier. The method also includes engaging a first switch component that is coupled to at least one of the first transformer or the second portion of the amplifier. Responsive to the engaging, the method additionally includes amplifying, by the second portion of the amplifier, the first signal to produce a partially-amplified signal. The method also includes routing the partially-amplified signal from the second portion of the amplifier, over a first signal path of a switch matrix, to a first portion of the amplifier. The method further includes amplifying, by the first portion of the amplifier, the partially-amplified signal to produce an amplified signal.

In an example aspect, an apparatus for processing a signal is disclosed. The apparatus includes multiple downlink pipes, with each respective downlink pipe of the multiple downlink pipes respectively comprising a first portion of an amplifier. The apparatus also includes a first port interface, which includes a first transformer. The first port interface also includes a second portion of a respective amplifier of a downlink pipe of the multiple downlink pipes, with the second portion of the respective amplifier coupled to the first transformer, and a first switch component coupled to the second portion of the respective amplifier. The first port interface further includes another second portion of another respective amplifier of another downlink pipe of the multiple downlink pipes, with the other second portion of the other respective amplifier coupled to the first transformer, and another first switch component coupled to the other second portion of the other respective amplifier. The apparatus further includes a switch matrix. The switch matrix couples the second portion of the respective amplifier to the first portion of the respective amplifier of the downlink pipe of the multiple downlink pipes. The switch matrix also couples the other second portion of the other respective amplifier to the first portion of the other respective amplifier of the other downlink pipe of the multiple downlink pipes.

